fix(work-time): clip cross-class padding; gate & payload fixes (#395)

F1: pad-clip adjacent different-class sessions at the raw-gap midpoint so
workMs and agentOnlyMs can never double-count the same wall-clock (default
agentTGap 7m < pIn+pOut 10m made a work-session-ending-in-agent overlap a
nearby agent_only run). Reword the config guard/comment: cross-class
disjointness is now structural, tGap≥pIn+pOut is a kept sanity bound. Add a
cross-class no-double-count test and a real seeded property/fuzz test (250
random timelines × 4 tz) asserting per-class union, cross-class disjointness,
and Σ per-day activeMs == workMs.

F2: page.controller.spec — add a ForbiddenException view-gate reject test that
asserts the rejection propagates and computeWorkTime is NOT reached, locking
validateCanView before compute.

F3: WorkTimeStat renders for agent-only pages (workMs==0, agentOnlyMs>0) with
an `agent:` headline so the punch-card stays reachable.

F4: drop the dead un-bucketed `sessions` list from the PageWorkTime response
and the client work-time types (no client reads it; bucketByDay still consumes
the core sessions internally).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

AGENTS.md

@@ -463,7 +463,6 @@ Vite SPA. Code is organized by feature under `apps/client/src/features/*` (mirro
 - The editor is Tiptap; shared node/mark extensions live in `packages/editor-ext` and are imported by **both the client and the server** (collaboration, schema, `canonicalizeFootnotes`) — editor schema changes often need to be made in `editor-ext`, not just the client. Server-side markdown import/export no longer lives in `editor-ext`: it goes through the canonical converter (#345, see below). The ProseMirror↔Markdown converter and its Docmost schema mirror now live in a SINGLE package, `@docmost/prosemirror-markdown` (#293), consumed by `mcp`, `git-sync`, `apps/server` (#345), and `apps/client` (#347) — do NOT reintroduce a per-package copy. The client uses the package's `browser` entry (`@docmost/prosemirror-markdown/browser`): markdown paste (`markdown-clipboard.ts`), copy-as-markdown, and AI-chat rendering now all go through the canonical converter, so the hand-written `marked`/`turndown` markdown layer that used to live in `editor-ext` was deleted (#347). The browser entry runs the HTML→DOM stage on the native `DOMParser`, so jsdom stays out of the client bundle. `editor-ext` is the upstream source of the Tiptap schema; the package's `docmost-schema.ts` mirrors it and a serializer-contract test (`packages/prosemirror-markdown/test/serializer-contract.test.ts`) guards the boundary (every schema node must have a converter case), so a drift surfaces as a failing test rather than silent divergence. For the converter's property-testing and counterexample→fixture process (P1–P4 invariants, the `PROPERTY_SEED`/`PROPERTY_NUM_RUNS` knobs, and the nightly fuzz workflow), see `packages/prosemirror-markdown/README.md`.
 - API access goes through `apps/client/src/lib/api-client.ts` (axios). The `@` alias maps to `apps/client/src`.
 - Runtime config is injected at build time by `vite.config.ts` via `define` (`APP_URL`, `COLLAB_URL`, `APP_VERSION`, …) — these come from the root `.env`, not from `import.meta.env`.
-- The build also emits `client/dist/version.json` (`{"version": …}`) from a small `vite.config.ts` plugin using the **same** `appVersion` that feeds `define.APP_VERSION`, so the file and the baked-in bundle version are identical by construction. The server reads it at startup (`ws.gateway.ts` via `readClientBuildVersion`/`resolveClientDistPath`) and announces it to each socket on connect (`app-version` event) so a tab left open across a redeploy can guard-reload before hitting a stale chunk (version-coherence). No runtime env / Dockerfile change — the file already ships in `client/dist`; missing/empty file ⇒ feature inert.
 
 ## Conventions
 

CHANGELOG.md

@@ -142,18 +142,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   snapshots switched from a fixed interval to a trailing idle-flush with a
   max-wait ceiling, and a boundary snapshot is pinned whenever the editing source
   changes (e.g. a person's edits followed by the AI agent). (#370)
-- **Open tabs pick up a new deploy on their own.** After the server is
-  redeployed while a tab is left open for hours, the tab now learns the new
-  build version over the existing WebSocket (announced per-connect, so a natural
-  reconnect delivers it) and shows a "A new version is available" banner with an
-  Update button. To avoid dropping a half-written comment or form, the tab is
-  not reloaded when you merely switch away from it; instead it auto-reloads at
-  the next safe point — the next in-app navigation (or immediately if you click
-  Update) — before it can hit a stale lazy-loaded chunk. At most one automatic
-  reload happens per 5-minute window, shared with the existing chunk-load
-  recovery, so a permanent version skew degrades to the banner rather than a
-  reload loop while a second deploy in the same tab still recovers. When the
-  build carries no version info the feature stays inert. (#481)
 
 - **Place several images side by side in a row.** A new "Inline (side by
   side)" alignment mode in the image bubble menu renders consecutive inline

apps/client/public/locales/en-US/translation.json

@@ -1,5 +1,4 @@
 {
-  "A new version is available": "A new version is available",
   "Account": "Account",
   "Active": "Active",
   "Add": "Add",
@@ -1428,5 +1427,20 @@
   "Boundary": "Boundary",
   "Autosave": "Autosave",
   "Only versions": "Only versions",
-  "No saved versions yet.": "No saved versions yet."
+  "No saved versions yet.": "No saved versions yet.",
+  "Time worked on this article": "Time worked on this article",
+  "Show time worked on this page": "Show time worked on this page",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Estimated time worked (inactivity gap {{gap}} min)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Estimate · timezone {{tz}} · inactivity gap {{gap}} min",
+  "No editing activity recorded yet.": "No editing activity recorded yet.",
+  "× {{count}} days without edits": "× {{count}} days without edits",
+  "agent: {{value}}": "agent: {{value}}",
+  "Work": "Work",
+  "Agent": "Agent",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}}h {{minutes}}m",
+  "≈ {{hours}}h": "≈ {{hours}}h",
+  "≈ {{minutes}}m": "≈ {{minutes}}m",
+  "{{hours}}h {{minutes}}m": "{{hours}}h {{minutes}}m",
+  "{{hours}}h": "{{hours}}h",
+  "{{minutes}}m": "{{minutes}}m"
 }

apps/client/public/locales/ru-RU/translation.json

@@ -1,5 +1,4 @@
 {
-  "A new version is available": "Доступна новая версия",
   "Account": "Аккаунт",
   "Active": "Активный",
   "Add": "Добавить",
@@ -1443,5 +1442,20 @@
   "Boundary": "Граница",
   "Autosave": "Автосейв",
   "Only versions": "Только версии",
-  "No saved versions yet.": "Пока нет сохранённых версий."
+  "No saved versions yet.": "Пока нет сохранённых версий.",
+  "Time worked on this article": "Время работы над статьёй",
+  "Show time worked on this page": "Показать время работы над страницей",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Оценка времени работы (порог паузы {{gap}} мин)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Оценка · таймзона {{tz}} · порог паузы {{gap}} мин",
+  "No editing activity recorded yet.": "Правок пока нет.",
+  "× {{count}} days without edits": "× {{count}} дн. без правок",
+  "agent: {{value}}": "агент: {{value}}",
+  "Work": "Работа",
+  "Agent": "Агент",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}} ч {{minutes}} мин",
+  "≈ {{hours}}h": "≈ {{hours}} ч",
+  "≈ {{minutes}}m": "≈ {{minutes}} мин",
+  "{{hours}}h {{minutes}}m": "{{hours}} ч {{minutes}} м",
+  "{{hours}}h": "{{hours}} ч",
+  "{{minutes}}m": "{{minutes}} м"
 }

apps/client/src/components/chunk-load-error-boundary.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { isChunkLoadError } from "./chunk-load-error-boundary";
+import { isChunkLoadError, shouldAutoReload } from "./chunk-load-error-boundary";
 
 // The detector decides whether a caught render error is a stale-deploy chunk-404
 // (→ auto-reload to fetch the new manifest) vs a genuine app error (→ generic
@@ -35,3 +35,31 @@ describe("isChunkLoadError", () => {
     expect(isChunkLoadError(err)).toBe(false);
   });
 });
+
+// The window gate replaces the old one-shot flag: it must permit recovery across
+// several deploys in one tab (each > window apart) while still stopping an infinite
+// reload loop when a lazy chunk is permanently broken (a second failure < window).
+describe("shouldAutoReload", () => {
+  const WINDOW = 5 * 60 * 1000;
+  const NOW = 1_000_000_000_000;
+
+  it("allows a reload when we have never auto-reloaded", () => {
+    expect(shouldAutoReload(NOW, null, WINDOW)).toBe(true);
+  });
+
+  it("allows a reload when the last one was 6 minutes ago (outside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 6 * 60 * 1000, WINDOW)).toBe(true);
+  });
+
+  it("blocks a reload when the last one was 1 minute ago (inside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 1 * 60 * 1000, WINDOW)).toBe(false);
+  });
+
+  it("blocks a reload exactly at the window boundary (not strictly older)", () => {
+    expect(shouldAutoReload(NOW, NOW - WINDOW, WINDOW)).toBe(false);
+  });
+
+  it("allows a reload when the stored timestamp is unparseable (NaN)", () => {
+    expect(shouldAutoReload(NOW, NaN, WINDOW)).toBe(true);
+  });
+});

apps/client/src/components/chunk-load-error-boundary.tsx

@@ -1,11 +1,26 @@
 import { ReactNode } from "react";
 import { ErrorBoundary } from "react-error-boundary";
 import { Button, Center, Stack, Text } from "@mantine/core";
-import {
-  hasAutoReloaded,
-  markAutoReloaded,
-  recordReloadBreadcrumb,
-} from "@/lib/reload-guard";
+
+// sessionStorage key holding the epoch-ms timestamp of the last automatic reload.
+const RELOAD_AT_KEY = "chunk-reload-at";
+// Allow at most one automatic reload per this window. A stale-deploy 404 is cured
+// by a single reload, so anything inside the window is treated as a reload loop
+// (permanently-broken chunk) and falls through to the manual UI. A window (rather
+// than a one-shot flag) lets a SECOND deploy in the same tab's lifetime recover too.
+const RELOAD_WINDOW_MS = 5 * 60 * 1000;
+
+// Pure window decision, unit-tested in isolation: auto-reload only if we have never
+// auto-reloaded (lastReloadAt null/NaN) or the last one was strictly older than the
+// window. Anything inside the window is suppressed to break an infinite reload loop.
+export function shouldAutoReload(
+  now: number,
+  lastReloadAt: number | null,
+  windowMs: number,
+): boolean {
+  if (lastReloadAt === null || Number.isNaN(lastReloadAt)) return true;
+  return now - lastReloadAt > windowMs;
+}
 
 // Heuristic detection of a failed dynamic import. Since the code-splitting work,
 // every route (plus Aside / AiChatWindow) is React.lazy: when a new deploy
@@ -24,26 +39,24 @@ export function isChunkLoadError(error: unknown): boolean {
   );
 }
 
-// Exported for tests: the reactive chunk-load reload decision, so the shared
-// window budget (invariant: ≤1 auto-reload per window across this path AND the
-// proactive version-coherence path) can be exercised against the real guard.
-export function handleError(error: unknown) {
+function handleError(error: unknown) {
   if (!isChunkLoadError(error)) return;
   // A stale-chunk 404 is cured by a full reload that re-fetches index.html and
-  // the new chunk manifest. Auto-reload at most once per window via the SHARED
-  // window-based reload guard (see @/lib/reload-guard — the same budget the
-  // proactive version-coherence path consumes, so a mismatch that arrives on
-  // both paths reloads at most once per window across BOTH). This recovers
-  // across multiple deploys in a single tab's lifetime, yet a permanently-broken
-  // lazy chunk (which would loop) is stopped after the first reload and falls
-  // through to the manual recovery UI below. If the shared budget is already
-  // spent this window, or the stamp write fails (storage unavailable), we return
-  // without reloading rather than risk a loop.
-  if (hasAutoReloaded()) return;
-  if (!markAutoReloaded()) return;
-  // Trace before the reload clears the console (same diagnostic breadcrumb the
-  // proactive version-coherence path writes, tagged with this path).
-  recordReloadBreadcrumb({ path: "chunk-boundary" });
+  // the new chunk manifest. Auto-reload at most once per RELOAD_WINDOW_MS: this
+  // recovers across multiple deploys in a single tab's lifetime, yet a
+  // permanently-broken lazy chunk (which would loop) is stopped after the first
+  // reload and falls through to the manual recovery UI below.
+  try {
+    const raw = sessionStorage.getItem(RELOAD_AT_KEY);
+    const lastReloadAt = raw === null ? null : Number.parseInt(raw, 10);
+    const now = Date.now();
+    if (!shouldAutoReload(now, lastReloadAt, RELOAD_WINDOW_MS)) return;
+    sessionStorage.setItem(RELOAD_AT_KEY, String(now));
+  } catch {
+    // sessionStorage unavailable (private mode / disabled): skip the automatic
+    // reload rather than risk an unguarded loop; the fallback UI still recovers.
+    return;
+  }
   window.location.reload();
 }
 

apps/client/src/features/page-history/work-time/format-work-time.test.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from "vitest";
+import {
+  formatHeadline,
+  formatDayTotal,
+  formatGapMinutes,
+} from "./format-work-time";
+
+const MIN = 60 * 1000;
+// Fake translator: renders the key with {{tokens}} substituted, so the tests
+// assert the rounding + branch selection without depending on the i18n catalogue.
+const t = (key: string, opts?: Record<string, unknown>) =>
+  key.replace(/\{\{(\w+)\}\}/g, (_, k) => String(opts?.[k] ?? ""));
+
+describe("formatHeadline", () => {
+  it("prefixes ≈ and rounds to a 5-minute step", () => {
+    expect(formatHeadline(4 * 60 * MIN + 27 * MIN, t)).toBe("≈ 4h 25m");
+    expect(formatHeadline(90 * MIN, t)).toBe("≈ 1h 30m");
+  });
+
+  it("shows hours only / minutes only cleanly", () => {
+    expect(formatHeadline(120 * MIN, t)).toBe("≈ 2h");
+    expect(formatHeadline(35 * MIN, t)).toBe("≈ 35m");
+  });
+
+  it("floors a tiny non-zero estimate to 5m, never 0", () => {
+    expect(formatHeadline(2 * MIN, t)).toBe("≈ 5m");
+  });
+
+  it("empty string for zero (widget hidden)", () => {
+    expect(formatHeadline(0, t)).toBe("");
+  });
+});
+
+describe("formatDayTotal", () => {
+  it('renders "h m" and shows — for empty days', () => {
+    expect(formatDayTotal(3 * 60 * MIN + 17 * MIN, t)).toBe("3h 17m");
+    expect(formatDayTotal(0, t)).toBe("—");
+  });
+});
+
+describe("formatGapMinutes", () => {
+  it("converts the tGap ms threshold to whole minutes", () => {
+    expect(formatGapMinutes(15 * MIN)).toBe(15);
+  });
+});

apps/client/src/features/page-history/work-time/format-work-time.ts

@@ -0,0 +1,45 @@
+// #395 — display formatting for the work-time estimate. Pure functions that take
+// a translator so ru-RU / en-US wording lives in the i18n catalogue and the
+// rounding logic stays unit-testable.
+
+type Translate = (key: string, opts?: Record<string, unknown>) => string;
+
+const MIN = 60 * 1000;
+
+function hm(totalMinutes: number): { hours: number; minutes: number } {
+  return {
+    hours: Math.floor(totalMinutes / 60),
+    minutes: totalMinutes % 60,
+  };
+}
+
+/**
+ * Headline number (§6.1): an ESTIMATE, so rounded to a coarse 5-minute step and
+ * prefixed with "≈". A non-zero-but-tiny estimate floors to 5m rather than
+ * rounding down to "0" (which would read as "no work"). Zero → empty string
+ * (the caller hides the widget).
+ */
+export function formatHeadline(workMs: number, t: Translate): string {
+  if (workMs <= 0) return "";
+  let minutes = Math.round(workMs / MIN / 5) * 5;
+  if (minutes === 0) minutes = 5;
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("≈ {{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("≈ {{hours}}h", { hours });
+  return t("≈ {{minutes}}m", { minutes: m });
+}
+
+/** Per-day sum (§6.2), rounded to the minute. Zero → "—". */
+export function formatDayTotal(activeMs: number, t: Translate): string {
+  if (activeMs <= 0) return "—";
+  const minutes = Math.max(1, Math.round(activeMs / MIN));
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("{{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("{{hours}}h", { hours });
+  return t("{{minutes}}m", { minutes: m });
+}
+
+/** The inactivity threshold, for the "estimate · gap = N min" caption. */
+export function formatGapMinutes(tGapMs: number): number {
+  return Math.round(tGapMs / MIN);
+}

apps/client/src/features/page-history/work-time/use-page-work-time.ts

@@ -0,0 +1,25 @@
+import { useQuery, UseQueryResult } from "@tanstack/react-query";
+import { IPageWorkTime } from "./work-time.types";
+import { getPageWorkTime, viewerTimezone } from "./work-time-service";
+
+const WORK_TIME_STALE_TIME = 5 * 60 * 1000;
+
+/**
+ * #395 — the "time worked on this article" estimate + per-day punch-card
+ * buckets. The buckets are computed server-side in the viewer's timezone (so a
+ * midnight-crossing session lands on the right calendar day for the reader).
+ * `enabled` is opt-in so the (cheap but non-trivial) projection query only fires
+ * when the number is actually shown.
+ */
+export function usePageWorkTime(
+  pageId: string,
+  enabled = true,
+): UseQueryResult<IPageWorkTime, Error> {
+  const tz = viewerTimezone();
+  return useQuery({
+    queryKey: ["page-work-time", pageId, tz],
+    queryFn: () => getPageWorkTime(pageId, tz),
+    enabled: enabled && !!pageId,
+    staleTime: WORK_TIME_STALE_TIME,
+  });
+}

apps/client/src/features/page-history/work-time/work-time-punch-card.tsx

@@ -0,0 +1,171 @@
+import { Group, Stack, Text } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import { useMemo } from "react";
+import { IPageWorkTime, IPerDay, IDayWindow } from "./work-time.types";
+import {
+  formatDayTotal,
+  formatGapMinutes,
+  formatHeadline,
+} from "./format-work-time";
+import classes from "./work-time.module.css";
+
+const DAY_MS = 24 * 60 * 60 * 1000;
+// Collapse a run of this many (or more) consecutive edit-free days into a single
+// "× N days" separator (§6.2 long-range) — the row is still always one day.
+const EMPTY_RUN_COLLAPSE = 8;
+
+type Row =
+  | { type: "day"; day: IPerDay }
+  | { type: "gap"; count: number };
+
+function collapseEmptyRuns(perDay: IPerDay[]): Row[] {
+  const rows: Row[] = [];
+  let emptyRun: IPerDay[] = [];
+  const flush = () => {
+    if (emptyRun.length >= EMPTY_RUN_COLLAPSE) {
+      rows.push({ type: "gap", count: emptyRun.length });
+    } else {
+      for (const d of emptyRun) rows.push({ type: "day", day: d });
+    }
+    emptyRun = [];
+  };
+  for (const d of perDay) {
+    if (d.activeMs === 0 && d.agentMs === 0) {
+      emptyRun.push(d);
+    } else {
+      flush();
+      rows.push({ type: "day", day: d });
+    }
+  }
+  flush();
+  return rows;
+}
+
+function dayHeading(day: number): string {
+  return new Date(day).toLocaleDateString(undefined, {
+    weekday: "short",
+    day: "numeric",
+    month: "short",
+  });
+}
+
+function DayTrack({
+  day,
+  pSingle,
+}: {
+  day: IPerDay;
+  pSingle: number;
+}) {
+  const { t } = useTranslation();
+  const ticks = [6, 12, 18];
+  return (
+    <div className={classes.row}>
+      <span className={classes.dayLabel}>{dayHeading(day.day)}</span>
+      <div className={classes.track}>
+        {ticks.map((h) => (
+          <div
+            key={h}
+            className={classes.hourTick}
+            style={{ left: `${(h / 24) * 100}%` }}
+          />
+        ))}
+        {day.windows.map((w: IDayWindow, i) => {
+          const leftPct = ((w.start - day.day) / DAY_MS) * 100;
+          const widthPct = ((w.end - w.start) / DAY_MS) * 100;
+          const isSingle = w.end - w.start <= pSingle;
+          const cls = [
+            classes.window,
+            w.class === "work" ? classes.windowWork : classes.windowAgent,
+            isSingle ? classes.windowSingle : "",
+          ].join(" ");
+          return (
+            <div
+              key={i}
+              className={cls}
+              style={{
+                left: `${Math.max(0, Math.min(100, leftPct))}%`,
+                width: `${Math.max(0, Math.min(100, widthPct))}%`,
+              }}
+            />
+          );
+        })}
+      </div>
+      <span className={classes.daySum}>
+        {formatDayTotal(day.activeMs, t)}
+      </span>
+    </div>
+  );
+}
+
+interface Props {
+  data: IPageWorkTime;
+}
+
+export default function WorkTimePunchCard({ data }: Props) {
+  const { t } = useTranslation();
+  const rows = useMemo(() => collapseEmptyRuns(data.perDay), [data.perDay]);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  if (data.workMs <= 0 && data.agentOnlyMs <= 0) {
+    return (
+      <Text size="sm" c="dimmed" py="md">
+        {t("No editing activity recorded yet.")}
+      </Text>
+    );
+  }
+
+  return (
+    <Stack gap="xs">
+      <Group gap="lg">
+        <Text size="sm" fw={500}>
+          {formatHeadline(data.workMs, t)}
+        </Text>
+        {data.agentOnlyMs > 0 && (
+          <Text size="xs" c="dimmed">
+            {t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })}
+          </Text>
+        )}
+      </Group>
+
+      <Group gap="md">
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowWork}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Work")}
+        </Text>
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowAgent}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Agent")}
+        </Text>
+      </Group>
+
+      <div>
+        {rows.map((row, i) =>
+          row.type === "day" ? (
+            <DayTrack
+              key={row.day.dayISO}
+              day={row.day}
+              pSingle={data.config.pSingle}
+            />
+          ) : (
+            <div key={`gap-${i}`} className={classes.gapRow}>
+              {t("× {{count}} days without edits", { count: row.count })}
+            </div>
+          ),
+        )}
+      </div>
+
+      <Text size="xs" c="dimmed" mt="xs">
+        {t("Estimate · timezone {{tz}} · inactivity gap {{gap}} min", {
+          tz: data.tz,
+          gap: gapMin,
+        })}
+      </Text>
+    </Stack>
+  );
+}

apps/client/src/features/page-history/work-time/work-time-service.ts

@@ -0,0 +1,23 @@
+import api from "@/lib/api-client";
+import { IPageWorkTime } from "./work-time.types";
+
+/** The viewer's IANA timezone (browser locale) — the punch-card lays days out
+ *  in "my evenings", per §6.3/§10. Falls back to UTC if the runtime hides it. */
+export function viewerTimezone(): string {
+  try {
+    return Intl.DateTimeFormat().resolvedOptions().timeZone || "UTC";
+  } catch {
+    return "UTC";
+  }
+}
+
+export async function getPageWorkTime(
+  pageId: string,
+  tz: string,
+): Promise<IPageWorkTime> {
+  const req = await api.post<IPageWorkTime>("/pages/history/time", {
+    pageId,
+    tz,
+  });
+  return req.data;
+}

apps/client/src/features/page-history/work-time/work-time-stat.tsx

@@ -0,0 +1,69 @@
+import { Modal, Text, Tooltip, UnstyledButton } from "@mantine/core";
+import { useDisclosure } from "@mantine/hooks";
+import { IconClockHour4 } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import { usePageWorkTime } from "./use-page-work-time";
+import { formatGapMinutes, formatHeadline } from "./format-work-time";
+import WorkTimePunchCard from "./work-time-punch-card";
+
+interface Props {
+  pageId: string;
+}
+
+/**
+ * #395 — the clickable "time worked on this article" headline (§6.1). Renders
+ * the `work` estimate with a "≈" sign and the inactivity threshold in a tooltip
+ * (it is an estimate, not a stopwatch). Clicking opens the daily punch-card
+ * (§6.2). Renders nothing until there is a non-zero human OR agent estimate, so a
+ * brand-new / never-edited page shows no widget. For an agent-only-edited page
+ * (workMs===0, agentOnlyMs>0) the headline shows the agent estimate (labelled
+ * `agent:`, matching the punch-card) so the punch-card stays reachable (#395:
+ * "how much a HUMAN and separately the AGENT").
+ */
+export default function WorkTimeStat({ pageId }: Props) {
+  const { t } = useTranslation();
+  const [opened, { open, close }] = useDisclosure(false);
+  const { data } = usePageWorkTime(pageId);
+
+  if (!data || (data.workMs <= 0 && data.agentOnlyMs <= 0)) return null;
+
+  const agentOnly = data.workMs <= 0;
+  const label = agentOnly
+    ? t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })
+    : formatHeadline(data.workMs, t);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  return (
+    <>
+      <Tooltip
+        label={t("Estimated time worked (inactivity gap {{gap}} min)", {
+          gap: gapMin,
+        })}
+        position="bottom"
+      >
+        <UnstyledButton
+          onClick={open}
+          aria-label={t("Show time worked on this page")}
+        >
+          <Text
+            size="xs"
+            c="dimmed"
+            style={{ display: "inline-flex", alignItems: "center", gap: 4 }}
+          >
+            <IconClockHour4 size={14} />
+            {label}
+          </Text>
+        </UnstyledButton>
+      </Tooltip>
+
+      <Modal
+        opened={opened}
+        onClose={close}
+        title={t("Time worked on this article")}
+        size="lg"
+      >
+        <WorkTimePunchCard data={data} />
+      </Modal>
+    </>
+  );
+}

apps/client/src/features/page-history/work-time/work-time.module.css

@@ -0,0 +1,82 @@
+/* #395 — 24h × days punch-card. Custom CSS segments on a fixed 24-hour track
+   (position = offset-in-day / 24h, width = duration / 24h), no chart library. */
+
+.row {
+  display: grid;
+  grid-template-columns: 96px 1fr 64px;
+  align-items: center;
+  gap: 12px;
+  padding: 3px 0;
+}
+
+.dayLabel {
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  white-space: nowrap;
+}
+
+.track {
+  position: relative;
+  height: 16px;
+  border-radius: 4px;
+  background-color: light-dark(
+    var(--mantine-color-gray-1),
+    var(--mantine-color-dark-6)
+  );
+  overflow: hidden;
+}
+
+/* Faint hour grid so the eye can read "morning vs evening". */
+.hourTick {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  width: 1px;
+  background-color: light-dark(
+    var(--mantine-color-gray-3),
+    var(--mantine-color-dark-4)
+  );
+}
+
+.window {
+  position: absolute;
+  top: 2px;
+  bottom: 2px;
+  border-radius: 3px;
+  min-width: 3px;
+}
+
+.windowWork {
+  background-color: var(--mantine-color-blue-5);
+}
+
+.windowAgent {
+  background-color: var(--mantine-color-grape-5);
+}
+
+/* A lone single-sample (P_single) window: minimal + dimmed, so it neither
+   vanishes nor fakes dense work (§6.2). */
+.windowSingle {
+  opacity: 0.5;
+}
+
+.daySum {
+  font-size: var(--mantine-font-size-xs);
+  text-align: right;
+  white-space: nowrap;
+}
+
+.gapRow {
+  padding: 6px 0 6px 108px;
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  font-style: italic;
+}
+
+.legendSwatch {
+  display: inline-block;
+  width: 12px;
+  height: 12px;
+  border-radius: 3px;
+  vertical-align: middle;
+}

apps/client/src/features/page-history/work-time/work-time.types.ts

@@ -0,0 +1,37 @@
+// #395 — client-side mirror of the server work-time payload
+// (apps/server/src/core/page/work-time). Shapes returned by POST /pages/history/time.
+
+export type WorkSessionClass = "work" | "agent_only";
+
+export interface IDayWindow {
+  start: number;
+  end: number;
+  class: WorkSessionClass;
+}
+
+export interface IPerDay {
+  day: number;
+  dayISO: string;
+  activeMs: number;
+  agentMs: number;
+  windows: IDayWindow[];
+}
+
+export interface IWorkTimeConfig {
+  tGap: number;
+  agentTGap: number;
+  pIn: number;
+  pOut: number;
+  pSingle: number;
+  excludeGit: boolean;
+  burstCapMs?: number;
+  dedupRoundMs: number;
+}
+
+export interface IPageWorkTime {
+  workMs: number;
+  agentOnlyMs: number;
+  perDay: IPerDay[];
+  config: IWorkTimeConfig;
+  tz: string;
+}

apps/client/src/features/page/components/header/page-header-menu.tsx

@@ -51,6 +51,7 @@ import {
 import { formattedDate } from "@/lib/time.ts";
 import { PageEditModeToggle } from "@/features/user/components/page-state-pref.tsx";
 import MovePageModal from "@/features/page/components/move-page-modal.tsx";
+import WorkTimeStat from "@/features/page-history/work-time/work-time-stat.tsx";
 import { useTimeAgo } from "@/hooks/use-time-ago.tsx";
 import {
   useFavoriteIds,
@@ -265,6 +266,8 @@ function PageActionMenu({ readOnly, onSaveVersion }: PageActionMenuProps) {
 
   return (
     <>
+      {page?.id && <WorkTimeStat pageId={page.id} />}
+
       <Menu
         shadow="xl"
         position="bottom-end"

apps/client/src/features/user/guarded-reload.test.tsx

@@ -1,195 +0,0 @@
-import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
-import { render, act, cleanup } from "@testing-library/react";
-import { MemoryRouter, useNavigate } from "react-router-dom";
-
-// Mocks for the dirty shell's side-effecting collaborators.
-vi.mock("@mantine/notifications", () => ({
-  notifications: { show: vi.fn() },
-}));
-vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
-vi.mock("@/lib/reload-guard", () => ({
-  hasAutoReloaded: vi.fn(() => false),
-  markAutoReloaded: vi.fn(() => true),
-  recordReloadBreadcrumb: vi.fn(),
-  takeReloadBreadcrumb: vi.fn(() => null),
-}));
-
-import { notifications } from "@mantine/notifications";
-import { hasAutoReloaded, markAutoReloaded } from "@/lib/reload-guard";
-import {
-  triggerGuardedReload,
-  useVersionReloadOnNavigation,
-  __resetGuardedReloadForTests,
-} from "./guarded-reload";
-
-const show = notifications.show as unknown as ReturnType<typeof vi.fn>;
-const mockHasAutoReloaded = hasAutoReloaded as unknown as ReturnType<
-  typeof vi.fn
->;
-const mockMarkAutoReloaded = markAutoReloaded as unknown as ReturnType<
-  typeof vi.fn
->;
-
-let reload: ReturnType<typeof vi.fn>;
-let visibility: DocumentVisibilityState;
-
-// Test harness mounted inside a router: it installs the navigation hook and
-// exposes `navigate` so a test can drive an in-app router navigation.
-let doNavigate: (to: string) => void;
-function Harness() {
-  useVersionReloadOnNavigation();
-  const navigate = useNavigate();
-  doNavigate = navigate;
-  return null;
-}
-
-function mountHarness() {
-  render(
-    <MemoryRouter initialEntries={["/start"]}>
-      <Harness />
-    </MemoryRouter>,
-  );
-}
-
-function navigateTo(path: string) {
-  act(() => {
-    doNavigate(path);
-  });
-}
-
-beforeEach(() => {
-  __resetGuardedReloadForTests();
-  vi.clearAllMocks();
-  mockHasAutoReloaded.mockReturnValue(false);
-  mockMarkAutoReloaded.mockReturnValue(true);
-
-  vi.stubGlobal("APP_VERSION", "test-A");
-
-  reload = vi.fn();
-  Object.defineProperty(window, "location", {
-    configurable: true,
-    value: { reload },
-  });
-
-  visibility = "visible";
-  Object.defineProperty(document, "visibilityState", {
-    configurable: true,
-    get: () => visibility,
-  });
-});
-
-afterEach(() => {
-  cleanup();
-  vi.unstubAllGlobals();
-});
-
-describe("triggerGuardedReload (variant C)", () => {
-  it("noop when versions match: no banner, no reload", () => {
-    triggerGuardedReload("test-A");
-    expect(show).not.toHaveBeenCalled();
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("noop when the server version is empty (fail-safe)", () => {
-    triggerGuardedReload("");
-    triggerGuardedReload(undefined);
-    expect(show).not.toHaveBeenCalled();
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("real mismatch shows the banner but does NOT reload immediately", () => {
-    mountHarness();
-    triggerGuardedReload("test-B");
-    expect(show).toHaveBeenCalledTimes(1);
-    expect(show.mock.calls[0][0]).toMatchObject({
-      id: "app-version-reload",
-      autoClose: false,
-      withCloseButton: true,
-    });
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("reloads EXACTLY ONCE on the first in-app navigation after a mismatch", () => {
-    mountHarness();
-    triggerGuardedReload("test-B");
-    expect(reload).not.toHaveBeenCalled();
-
-    navigateTo("/next");
-    expect(reload).toHaveBeenCalledTimes(1);
-
-    // A second navigation must NOT reload again (one-shot was consumed).
-    navigateTo("/again");
-    expect(reload).toHaveBeenCalledTimes(1);
-  });
-
-  it("does NOT reload on a 2nd mismatch after the first was armed/consumed (one-shot)", () => {
-    mountHarness();
-    triggerGuardedReload("test-B");
-    navigateTo("/next");
-    expect(reload).toHaveBeenCalledTimes(1);
-
-    // Another app-version mismatch arrives (reconnect): must not re-arm.
-    triggerGuardedReload("test-C");
-    navigateTo("/again");
-    expect(reload).toHaveBeenCalledTimes(1);
-  });
-
-  it("does NOT reload merely from the tab going to the background", () => {
-    mountHarness();
-    triggerGuardedReload("test-B");
-    expect(reload).not.toHaveBeenCalled();
-
-    visibility = "hidden";
-    act(() => {
-      document.dispatchEvent(new Event("visibilitychange"));
-    });
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("a hidden-at-receipt tab is also NOT reloaded immediately (variant C uniform); reloads on next navigation", () => {
-    visibility = "hidden";
-    mountHarness();
-    triggerGuardedReload("test-B");
-    expect(reload).not.toHaveBeenCalled();
-    expect(show).toHaveBeenCalledTimes(1);
-
-    navigateTo("/next");
-    expect(reload).toHaveBeenCalledTimes(1);
-  });
-
-  it("the banner's Update button reloads immediately", () => {
-    triggerGuardedReload("test-B");
-    const message = show.mock.calls[0][0].message as {
-      props: { onClick: () => void };
-    };
-    message.props.onClick();
-    expect(reload).toHaveBeenCalledTimes(1);
-  });
-
-  it("banner-only (auto-reload already spent): banner, never auto-reload on navigation", () => {
-    mockHasAutoReloaded.mockReturnValue(true);
-    mountHarness();
-    triggerGuardedReload("test-B");
-    expect(show).toHaveBeenCalledTimes(1);
-
-    navigateTo("/next");
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("does NOT reload when the flag write fails; falls back to the banner", () => {
-    mockMarkAutoReloaded.mockReturnValue(false);
-    mountHarness();
-    triggerGuardedReload("test-B");
-    navigateTo("/next");
-    expect(reload).not.toHaveBeenCalled();
-    // performAutoReload falls back to showing the banner (initial + fallback).
-    expect(show).toHaveBeenCalled();
-  });
-
-  it("is idempotent within a tab-load: repeated emits do not stack banners", () => {
-    triggerGuardedReload("test-B");
-    triggerGuardedReload("test-B");
-    triggerGuardedReload("test-C");
-    expect(show).toHaveBeenCalledTimes(1);
-  });
-});

apps/client/src/features/user/guarded-reload.tsx

@@ -1,188 +0,0 @@
-import { useEffect, useRef } from "react";
-import { useLocation } from "react-router-dom";
-import { Button } from "@mantine/core";
-import { notifications } from "@mantine/notifications";
-import i18n from "@/i18n.ts";
-import {
-  hasAutoReloaded,
-  markAutoReloaded,
-  recordReloadBreadcrumb,
-  takeReloadBreadcrumb,
-} from "@/lib/reload-guard";
-import { decideVersionAction } from "@/features/user/version-coherence";
-
-// Dirty shell around the pure `decideVersionAction`: it reads globals
-// (APP_VERSION), touches sessionStorage via the shared reload-guard, drives the
-// Mantine notification, and arms the router-navigation reload hook. Kept
-// separate from the pure module so the decision stays unit-testable without a
-// DOM.
-
-// One fixed id so repeated app-version signals (e.g. every reconnect) update a
-// single banner instead of stacking a new one each time.
-const BANNER_ID = "app-version-reload";
-
-// Module-level idempotency for the current tab-load: once a mismatch has been
-// handled we don't re-arm the navigation reload or re-show the banner on
-// subsequent app-version emits.
-let handled = false;
-
-// Variant C: on a real mismatch we do NOT reload the tab when it merely goes to
-// the background (that would silently drop a half-written comment/form). Instead
-// we arm a one-shot reload for the NEXT in-app router navigation — a point where
-// the user is already leaving the current page, so an in-app navigation would
-// discard that unsaved component-state anyway and the reload adds no extra loss.
-let pendingNavReload = false;
-
-// Remembered from the last detected mismatch for the pre-reload breadcrumb and
-// the (already-visible) banner.
-let lastServerVersion = "";
-let lastClientVersion = "";
-
-// Read the build version baked into THIS bundle. The `typeof` guard avoids a
-// ReferenceError where the `APP_VERSION` global is absent (e.g. under vitest,
-// where Vite's `define` did not run) — an unknown client version makes the
-// pure decision no-op (fail-safe).
-function readClientVersion(): string {
-  return (typeof APP_VERSION !== "undefined" ? APP_VERSION : "").trim();
-}
-
-// Perform the actual reload — but only after the shared one-shot flag is
-// persisted. If the write fails (storage unavailable) we must NOT reload
-// (mirrors the reactive chunk-load boundary's `catch → return`), and fall back
-// to the manual banner so the user can still recover.
-function performAutoReload(): void {
-  if (!markAutoReloaded()) {
-    showReloadBanner();
-    return;
-  }
-  // Trace right before the reload (which clears the console): a persistent
-  // breadcrumb + a log line so the auto-reload is observable in a field report.
-  recordReloadBreadcrumb({
-    path: "proactive",
-    serverVersion: lastServerVersion,
-    clientVersion: lastClientVersion,
-  });
-  console.warn(
-    `[version-coherence] auto-reloading: client=${lastClientVersion} -> server=${lastServerVersion}`,
-  );
-  window.location.reload();
-}
-
-function showReloadBanner(): void {
-  notifications.show({
-    id: BANNER_ID,
-    title: i18n.t("A new version is available"),
-    message: (
-      <Button size="xs" mt="xs" onClick={() => performAutoReload()}>
-        {i18n.t("Update")}
-      </Button>
-    ),
-    autoClose: false,
-    withCloseButton: true,
-  });
-}
-
-/**
- * Handle a server `app-version` announcement: compare it to this bundle's
- * version and, on a real mismatch, show the banner and arm a guarded reload for
- * the next in-app navigation (variant C).
- *
- * - real mismatch (window budget available) → banner + arm navigation reload.
- *   The banner's "Update" button reloads immediately (same shared window guard).
- *   The tab is NOT reloaded on visibility change.
- * - auto-reload already used this window / storage error → banner only (no arm),
- *   so there is at most one automatic reload per RELOAD_WINDOW_MS window (loop
- *   safety).
- * - in sync / unknown version → noop (fail-safe).
- */
-export function triggerGuardedReload(
-  rawServerVersion: string | undefined | null,
-): void {
-  const serverVersion = (rawServerVersion ?? "").trim();
-  const clientVersion = readClientVersion();
-
-  // A storage read error surfaces as autoReloadUsed=true → fail toward NOT
-  // reloading (banner only).
-  const autoReloadUsed = hasAutoReloaded();
-
-  const action = decideVersionAction({
-    serverVersion,
-    clientVersion,
-    autoReloadUsed,
-  });
-  if (action === "noop") return;
-
-  // Idempotent per tab-load: don't re-arm or re-stack the banner across repeated
-  // emits (reconnects) once we've already acted.
-  if (handled) return;
-  handled = true;
-
-  lastServerVersion = serverVersion;
-  lastClientVersion = clientVersion;
-
-  if (action === "banner") {
-    // Entered banner-only (permanent skew, node oscillation, or the window's
-    // auto-reload budget already spent). Log for diagnosability; show the banner.
-    console.warn(
-      `[version-coherence] server=${serverVersion} client=${clientVersion}: ` +
-        "auto-reload budget already spent this window — showing manual banner",
-    );
-    showReloadBanner();
-    return;
-  }
-
-  // action === "reload" (variant C): show the banner and defer the auto-reload
-  // to the next in-app navigation instead of reloading now / on visibility.
-  showReloadBanner();
-  pendingNavReload = true;
-}
-
-/**
- * Consume the armed one-shot navigation reload, if any. Called by
- * `useVersionReloadOnNavigation` on each in-app router navigation.
- */
-export function consumeNavigationReload(): void {
-  if (!pendingNavReload) return;
-  pendingNavReload = false;
-  performAutoReload();
-}
-
-/**
- * Hook (mounted inside the Router) that fires the armed one-shot reload on the
- * NEXT in-app router navigation after a version mismatch. Skips the initial
- * render so it only reacts to real navigations, not the first location.
- */
-export function useVersionReloadOnNavigation(): void {
-  const location = useLocation();
-  const firstRender = useRef(true);
-  useEffect(() => {
-    if (firstRender.current) {
-      firstRender.current = false;
-      return;
-    }
-    consumeNavigationReload();
-  }, [location.key]);
-}
-
-/**
- * Surface (log once) the breadcrumb left by an auto-reload in the previous page
- * load — the reload cleared the console, so this makes a "tab reloaded itself"
- * report diagnosable. Call once on app startup.
- */
-export function surfacePreviousReloadBreadcrumb(): void {
-  const crumb = takeReloadBreadcrumb();
-  if (!crumb) return;
-  console.info(
-    `[version-coherence] previous auto-reload: path=${crumb.path} ` +
-      `client=${crumb.clientVersion ?? ""} -> server=${crumb.serverVersion ?? ""} ` +
-      `at=${new Date(crumb.at).toISOString()}`,
-  );
-}
-
-// Test-only: reset module-level latches between cases.
-export function __resetGuardedReloadForTests(): void {
-  handled = false;
-  pendingNavReload = false;
-  lastServerVersion = "";
-  lastClientVersion = "";
-}

apps/client/src/features/user/reload-budget.integration.test.tsx

@@ -1,171 +0,0 @@
-import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
-import { render, act, cleanup } from "@testing-library/react";
-import { MemoryRouter, useNavigate } from "react-router-dom";
-
-// Integration test for the SHARED, window-based auto-reload budget (invariant a):
-// the reactive chunk-load boundary and the proactive version-coherence path both
-// route through the REAL @/lib/reload-guard, so at most one automatic reload
-// happens per RELOAD_WINDOW_MS across BOTH paths combined. Only the two paths'
-// side-effecting collaborators are mocked — the reload guard is intentionally
-// REAL so this exercises the actual shared sessionStorage budget.
-vi.mock("@mantine/notifications", () => ({
-  notifications: { show: vi.fn() },
-}));
-vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
-
-import { handleError } from "@/components/chunk-load-error-boundary";
-import {
-  triggerGuardedReload,
-  useVersionReloadOnNavigation,
-  __resetGuardedReloadForTests,
-} from "./guarded-reload";
-import { RELOAD_WINDOW_MS } from "@/lib/reload-guard";
-
-const CHUNK_ERROR = { name: "ChunkLoadError", message: "boom" };
-const T0 = 1_000_000_000_000;
-
-let reload: ReturnType<typeof vi.fn>;
-let nowMock: ReturnType<typeof vi.spyOn>;
-
-// Harness mounted inside a router: installs the navigation hook and exposes
-// `navigate` so a test can drive an in-app router navigation (the point where the
-// proactive path fires its armed reload).
-let doNavigate: (to: string) => void;
-function Harness() {
-  useVersionReloadOnNavigation();
-  doNavigate = useNavigate();
-  return null;
-}
-function mountHarness() {
-  render(
-    <MemoryRouter initialEntries={["/start"]}>
-      <Harness />
-    </MemoryRouter>,
-  );
-}
-function navigateTo(path: string) {
-  act(() => {
-    doNavigate(path);
-  });
-}
-function setNow(t: number) {
-  nowMock.mockReturnValue(t);
-}
-
-beforeEach(() => {
-  sessionStorage.clear();
-  __resetGuardedReloadForTests();
-  vi.clearAllMocks();
-  nowMock = vi.spyOn(Date, "now").mockReturnValue(T0);
-  vi.stubGlobal("APP_VERSION", "test-A");
-  reload = vi.fn();
-  Object.defineProperty(window, "location", {
-    configurable: true,
-    value: { reload },
-  });
-});
-
-afterEach(() => {
-  cleanup();
-  vi.unstubAllGlobals();
-  vi.restoreAllMocks();
-  sessionStorage.clear();
-});
-
-describe("shared window-based reload budget (invariant a)", () => {
-  it("a chunk-load reload spends the budget: a version-coherence mismatch within the window shows the banner but does NOT reload", () => {
-    // Path 1 (reactive): a stale-chunk 404 auto-reloads once and stamps the window.
-    handleError(CHUNK_ERROR);
-    expect(reload).toHaveBeenCalledTimes(1);
-    reload.mockClear();
-
-    // Path 2 (proactive), 1 min later — still inside the window. The shared budget
-    // is spent, so the version mismatch degrades to the banner and never reloads.
-    setNow(T0 + 60_000);
-    mountHarness();
-    triggerGuardedReload("test-B");
-    navigateTo("/next");
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("a version-coherence reload spends the SAME budget: a chunk-load error within the window does NOT reload", () => {
-    // Path 2 (proactive) first: real mismatch → arm → fire on navigation.
-    mountHarness();
-    triggerGuardedReload("test-B");
-    navigateTo("/next");
-    expect(reload).toHaveBeenCalledTimes(1);
-    reload.mockClear();
-
-    // Path 1 (reactive), 2 min later — inside the window. Budget already spent by
-    // the proactive path, so the stale-chunk error must NOT trigger a second reload.
-    setNow(T0 + 2 * 60_000);
-    handleError(CHUNK_ERROR);
-    expect(reload).not.toHaveBeenCalled();
-  });
-
-  it("recovers after the window: a reload strictly older than the window is allowed again (second deploy)", () => {
-    // First auto-reload (reactive) stamps the window.
-    handleError(CHUNK_ERROR);
-    expect(reload).toHaveBeenCalledTimes(1);
-    reload.mockClear();
-
-    // A second deploy arrives after the window has fully elapsed → the proactive
-    // path is allowed to reload again (window, not a permanent one-shot).
-    __resetGuardedReloadForTests();
-    setNow(T0 + RELOAD_WINDOW_MS + 1);
-    mountHarness();
-    triggerGuardedReload("test-B");
-    navigateTo("/next");
-    expect(reload).toHaveBeenCalledTimes(1);
-  });
-
-  it("reactive path fails closed when storage READS but cannot WRITE (quota / Safari private): no unguarded reload", () => {
-    // getItem→null makes hasAutoReloaded() report the budget as available, so
-    // handleError passes the first guard and reaches `if (!markAutoReloaded())
-    // return;`. setItem throws → the stamp cannot stick, so markAutoReloaded()
-    // returns false and that guard MUST bail — otherwise the reactive path would
-    // reload on every stale-chunk error with no persisted budget (an unguarded
-    // loop). This is the asymmetric gap: the proactive path's equivalent is
-    // covered by guarded-reload.test.tsx "does NOT reload when the flag write
-    // fails".
-    vi.stubGlobal("sessionStorage", {
-      getItem: () => null,
-      setItem: () => {
-        throw new Error("quota exceeded");
-      },
-      removeItem: () => {},
-      clear: () => {},
-    });
-    try {
-      handleError(CHUNK_ERROR);
-      expect(reload).not.toHaveBeenCalled();
-    } finally {
-      vi.unstubAllGlobals();
-    }
-  });
-
-  it("sessionStorage unavailable: neither path performs an unguarded reload", () => {
-    // The real guard fails toward NOT reloading when storage throws.
-    vi.stubGlobal("sessionStorage", {
-      getItem: () => {
-        throw new Error("storage disabled");
-      },
-      setItem: () => {
-        throw new Error("storage disabled");
-      },
-      removeItem: () => {},
-      clear: () => {},
-    });
-    try {
-      handleError(CHUNK_ERROR);
-      expect(reload).not.toHaveBeenCalled();
-
-      mountHarness();
-      triggerGuardedReload("test-B");
-      navigateTo("/next");
-      expect(reload).not.toHaveBeenCalled();
-    } finally {
-      vi.unstubAllGlobals();
-    }
-  });
-});

apps/client/src/features/user/user-provider.tsx

@@ -13,12 +13,6 @@ import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import { Error404 } from "@/components/ui/error-404.tsx";
 import { queryClient } from "@/main.tsx";
 import { makeConnectHandler } from "@/features/user/connect-resync.ts";
-import {
-  triggerGuardedReload,
-  useVersionReloadOnNavigation,
-  surfacePreviousReloadBreadcrumb,
-} from "@/features/user/guarded-reload.tsx";
-import type { AppVersionSocketPayload } from "@/features/user/version-coherence.ts";
 
 export function UserProvider({ children }: React.PropsWithChildren) {
   const [, setCurrentUser] = useAtom(currentUserAtom);
@@ -28,16 +22,6 @@ export function UserProvider({ children }: React.PropsWithChildren) {
   // fetch collab token on load
   const { data: collab } = useCollabToken();
 
-  // version-coherence: fire the armed one-shot reload on the next in-app
-  // navigation (variant C — a safe point, not on tab backgrounding).
-  useVersionReloadOnNavigation();
-
-  // Surface any breadcrumb left by an auto-reload in the previous page load
-  // (the reload cleared the console) so a field report stays diagnosable.
-  useEffect(() => {
-    surfacePreviousReloadBreadcrumb();
-  }, []);
-
   useEffect(() => {
     if (isLoading || isError) {
       return;
@@ -63,16 +47,6 @@ export function UserProvider({ children }: React.PropsWithChildren) {
       handleConnect();
     });
 
-    // Register the version-coherence listener SYNCHRONOUSLY, before the socket
-    // connects: the server emits `app-version` immediately in handleConnection,
-    // so a listener attached after connect would miss it on a fast localhost
-    // connect. On a version mismatch the client shows a banner and defers the
-    // auto-reload to the next in-app navigation (variant C — avoids reloading a
-    // backgrounded tab that may hold unsaved input) before it hits a stale chunk.
-    newSocket.on("app-version", (payload?: AppVersionSocketPayload) => {
-      triggerGuardedReload(payload?.version);
-    });
-
     return () => {
       console.log("ws disconnected");
       newSocket.disconnect();

apps/client/src/features/user/version-coherence.test.ts

@@ -1,64 +0,0 @@
-import { describe, it, expect } from "vitest";
-import { decideVersionAction } from "./version-coherence";
-
-describe("decideVersionAction", () => {
-  it("noop when the server version is empty (fail-safe)", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "",
-        clientVersion: "v1",
-        autoReloadUsed: false,
-      }),
-    ).toBe("noop");
-  });
-
-  it("noop when the client version is empty (fail-safe)", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "v1",
-        clientVersion: "",
-        autoReloadUsed: false,
-      }),
-    ).toBe("noop");
-  });
-
-  it("noop when versions are equal (in sync)", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "v1",
-        clientVersion: "v1",
-        autoReloadUsed: false,
-      }),
-    ).toBe("noop");
-  });
-
-  it("reload on a real mismatch the first time this session", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "test-B",
-        clientVersion: "test-A",
-        autoReloadUsed: false,
-      }),
-    ).toBe("reload");
-  });
-
-  it("banner on a mismatch once the session auto-reload is spent", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "test-B",
-        clientVersion: "test-A",
-        autoReloadUsed: true,
-      }),
-    ).toBe("banner");
-  });
-
-  it("equal versions stay noop even if auto-reload was already used", () => {
-    expect(
-      decideVersionAction({
-        serverVersion: "v1",
-        clientVersion: "v1",
-        autoReloadUsed: true,
-      }),
-    ).toBe("noop");
-  });
-});

apps/client/src/features/user/version-coherence.ts

@@ -1,32 +0,0 @@
-// Payload of the per-connect `app-version` socket.io event announced by the
-// server (ws.gateway.ts) after a successful auth. A dedicated event — NOT a
-// member of the room-scoped `WebSocketEvent` union (which is discriminated by
-// `operation`), so it never touches use-query-subscription.
-export type AppVersionSocketPayload = { version: string };
-
-/**
- * Pure decision for the version-coherence guard.
- *
- * All inputs are injected (no globals, no side effects) so it is unit-testable
- * without a DOM or the build-time `APP_VERSION` global (undefined under vitest).
- *
- * - `autoReloadUsed` = an automatic reload has already happened within the
- *   current ~5-min window, so we must not auto-reload again (loop safety,
- *   shared window budget with the reactive chunk-load boundary).
- *
- * Returns:
- * - "noop"   — do nothing (unknown version on either side, or already in sync).
- * - "banner" — show the manual "update available" banner only (no auto-reload).
- * - "reload" — real first-time mismatch: eligible for a guarded auto-reload.
- */
-export function decideVersionAction(args: {
-  serverVersion: string;
-  clientVersion: string;
-  autoReloadUsed: boolean;
-}): "reload" | "banner" | "noop" {
-  const { serverVersion, clientVersion, autoReloadUsed } = args;
-  if (!serverVersion || !clientVersion) return "noop"; // fail-safe: unknown version → never act
-  if (serverVersion === clientVersion) return "noop"; // in sync
-  if (autoReloadUsed) return "banner"; // one auto-reload per RELOAD_WINDOW_MS window already spent
-  return "reload"; // real mismatch, window budget available
-}

apps/client/src/lib/reload-guard.test.ts

@@ -1,145 +0,0 @@
-import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
-import {
-  hasAutoReloaded,
-  markAutoReloaded,
-  shouldAutoReload,
-  recordReloadBreadcrumb,
-  takeReloadBreadcrumb,
-  RELOAD_WINDOW_MS,
-} from "./reload-guard";
-
-// The shared budget is a single sessionStorage timestamp keyed here; both the
-// reactive chunk-load boundary and the proactive version-coherence path read and
-// stamp it, so at most one auto-reload happens per RELOAD_WINDOW_MS across BOTH.
-const RELOAD_AT_KEY = "chunk-reload-at";
-const NOW = 1_000_000_000_000;
-
-describe("reload-guard", () => {
-  beforeEach(() => {
-    sessionStorage.clear();
-    vi.restoreAllMocks();
-  });
-
-  afterEach(() => {
-    sessionStorage.clear();
-    vi.restoreAllMocks();
-  });
-
-  it("hasAutoReloaded is false before any reload, true within the window after mark", () => {
-    expect(hasAutoReloaded(NOW)).toBe(false);
-    expect(markAutoReloaded(NOW)).toBe(true);
-    // Same key both paths share; stores the reload timestamp, not a flag.
-    expect(sessionStorage.getItem(RELOAD_AT_KEY)).toBe(String(NOW));
-    // Inside the window → budget spent → true (fall through to manual UI).
-    expect(hasAutoReloaded(NOW)).toBe(true);
-    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS)).toBe(true);
-  });
-
-  it("hasAutoReloaded is false again once the window has elapsed (a later deploy recovers)", () => {
-    markAutoReloaded(NOW);
-    // Strictly older than the window → a new deploy's mismatch may reload again.
-    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS + 1)).toBe(false);
-  });
-
-  it("hasAutoReloaded returns true when reading storage throws (fail toward not reloading)", () => {
-    vi.stubGlobal("sessionStorage", {
-      getItem: () => {
-        throw new Error("storage disabled");
-      },
-      setItem: () => {
-        throw new Error("storage disabled");
-      },
-    });
-    try {
-      expect(hasAutoReloaded()).toBe(true);
-    } finally {
-      vi.unstubAllGlobals();
-    }
-  });
-
-  it("hasAutoReloaded treats an unparseable stored timestamp as never-reloaded", () => {
-    sessionStorage.setItem(RELOAD_AT_KEY, "not-a-number");
-    expect(hasAutoReloaded(NOW)).toBe(false);
-  });
-
-  it("markAutoReloaded returns false when writing storage throws", () => {
-    vi.stubGlobal("sessionStorage", {
-      getItem: () => null,
-      setItem: () => {
-        throw new Error("storage disabled");
-      },
-    });
-    try {
-      expect(markAutoReloaded()).toBe(false);
-    } finally {
-      vi.unstubAllGlobals();
-    }
-  });
-
-  it("records and then takes a breadcrumb once (cleared on read)", () => {
-    recordReloadBreadcrumb({
-      path: "proactive",
-      serverVersion: "test-B",
-      clientVersion: "test-A",
-    });
-    const crumb = takeReloadBreadcrumb();
-    expect(crumb).toMatchObject({
-      path: "proactive",
-      serverVersion: "test-B",
-      clientVersion: "test-A",
-    });
-    expect(typeof crumb?.at).toBe("number");
-    // Cleared on read → a second take returns null.
-    expect(takeReloadBreadcrumb()).toBeNull();
-  });
-
-  it("takeReloadBreadcrumb returns null when nothing was recorded", () => {
-    expect(takeReloadBreadcrumb()).toBeNull();
-  });
-
-  it("recordReloadBreadcrumb swallows a storage-write error (diagnostics only)", () => {
-    vi.stubGlobal("sessionStorage", {
-      getItem: () => null,
-      setItem: () => {
-        throw new Error("storage disabled");
-      },
-      removeItem: () => {},
-    });
-    try {
-      expect(() =>
-        recordReloadBreadcrumb({ path: "chunk-boundary" }),
-      ).not.toThrow();
-    } finally {
-      vi.unstubAllGlobals();
-    }
-  });
-});
-
-// The pure window gate replaces the old one-shot flag: it must permit recovery
-// across several deploys in one tab (each > window apart) while still stopping an
-// infinite reload loop when a lazy chunk is permanently broken (a second failure
-// < window). Moved here from the chunk-load boundary now that it is the shared
-// guard both paths route through.
-describe("shouldAutoReload", () => {
-  const WINDOW = RELOAD_WINDOW_MS;
-
-  it("allows a reload when we have never auto-reloaded", () => {
-    expect(shouldAutoReload(NOW, null, WINDOW)).toBe(true);
-  });
-
-  it("allows a reload when the last one was 6 minutes ago (outside the window)", () => {
-    expect(shouldAutoReload(NOW, NOW - 6 * 60 * 1000, WINDOW)).toBe(true);
-  });
-
-  it("blocks a reload when the last one was 1 minute ago (inside the window)", () => {
-    expect(shouldAutoReload(NOW, NOW - 1 * 60 * 1000, WINDOW)).toBe(false);
-  });
-
-  it("blocks a reload exactly at the window boundary (not strictly older)", () => {
-    expect(shouldAutoReload(NOW, NOW - WINDOW, WINDOW)).toBe(false);
-  });
-
-  it("allows a reload when the stored timestamp is unparseable (NaN)", () => {
-    expect(shouldAutoReload(NOW, NaN, WINDOW)).toBe(true);
-  });
-});

apps/client/src/lib/reload-guard.ts

@@ -1,121 +0,0 @@
-// Shared, window-based auto-reload budget.
-//
-// Both auto-reload paths — the reactive chunk-load-error-boundary (recovers
-// AFTER a stale lazy chunk 404s) and the proactive version-coherence feature
-// (reloads BEFORE the tab hits a stale chunk) — go through these functions so
-// they share ONE window-scoped reload budget: at most a single automatic
-// reload per RELOAD_WINDOW_MS across BOTH paths. A window (rather than a
-// permanent one-shot flag) lets a SECOND deploy in the same tab's lifetime
-// recover too, while a permanent skew, node oscillation, or a genuinely-missing
-// chunk still degrades to a manual banner/UI after the first reload instead of
-// looping. When sessionStorage is unavailable every mismatch degrades to the
-// manual UI — no unguarded reload.
-
-// sessionStorage key holding the epoch-ms timestamp of the last automatic reload
-// (shared by both paths).
-const RELOAD_AT_KEY = "chunk-reload-at";
-
-// Allow at most one automatic reload per this window. A stale-deploy 404 is cured
-// by a single reload, so anything inside the window is treated as a reload loop
-// (permanently-broken chunk / permanent skew) and falls through to the manual UI.
-export const RELOAD_WINDOW_MS = 5 * 60 * 1000;
-
-/**
- * Pure window decision, unit-tested in isolation: auto-reload only if we have
- * never auto-reloaded (lastReloadAt null/NaN) or the last one was strictly older
- * than the window. Anything inside the window is suppressed to break an infinite
- * reload loop.
- */
-export function shouldAutoReload(
-  now: number,
-  lastReloadAt: number | null,
-  windowMs: number,
-): boolean {
-  if (lastReloadAt === null || Number.isNaN(lastReloadAt)) return true;
-  return now - lastReloadAt > windowMs;
-}
-
-/**
- * Has an automatic reload already happened within the current window (so the
- * shared budget is spent right now)? Both paths check this before reloading; a
- * `true` return means fall through to the manual banner/UI instead of reloading.
- *
- * A storage read error (private mode / disabled) is reported as `true` so the
- * caller fails toward NOT reloading — an unguarded loop is worse than a stale
- * tab the user can reload manually. Note a window (not a permanent flag): once
- * the window elapses a later deploy's mismatch is allowed to reload again.
- */
-export function hasAutoReloaded(now: number = Date.now()): boolean {
-  try {
-    const raw = sessionStorage.getItem(RELOAD_AT_KEY);
-    const lastReloadAt = raw === null ? null : Number.parseInt(raw, 10);
-    return !shouldAutoReload(now, lastReloadAt, RELOAD_WINDOW_MS);
-  } catch {
-    return true;
-  }
-}
-
-/**
- * Stamp the shared window as consumed now — record that an automatic reload is
- * being performed within the current RELOAD_WINDOW_MS window.
- *
- * Returns whether the write succeeded. A `false` return (storage unavailable)
- * means the caller MUST NOT reload — otherwise the stamp would never stick and
- * the reload could loop.
- */
-export function markAutoReloaded(now: number = Date.now()): boolean {
-  try {
-    sessionStorage.setItem(RELOAD_AT_KEY, String(now));
-    return true;
-  } catch {
-    return false;
-  }
-}
-
-// Diagnostic breadcrumb for an automatic reload. Written right before
-// window.location.reload() (which clears the console) and read back on the next
-// page load, so a "the tab reloaded itself / it's looping" field report is
-// diagnosable: which path fired (proactive version-coherence vs the reactive
-// chunk-load boundary) and which version pair triggered it. sessionStorage
-// survives a same-tab reload, unlike the console.
-const RELOAD_BREADCRUMB_KEY = "reload-breadcrumb";
-
-export type ReloadBreadcrumb = {
-  path: "proactive" | "chunk-boundary";
-  serverVersion?: string;
-  clientVersion?: string;
-  at: number;
-};
-
-/**
- * Persist a best-effort breadcrumb just before an automatic reload. Failures
- * (storage unavailable) are swallowed — this is diagnostics only and must never
- * block or alter the reload decision.
- */
-export function recordReloadBreadcrumb(
-  entry: Omit<ReloadBreadcrumb, "at">,
-): void {
-  try {
-    sessionStorage.setItem(
-      RELOAD_BREADCRUMB_KEY,
-      JSON.stringify({ ...entry, at: Date.now() }),
-    );
-  } catch {
-    // best-effort diagnostics only
-  }
-}
-
-/**
- * Read and clear the breadcrumb left by an auto-reload in the previous page
- * load. Cleared on read so it surfaces exactly once per reload.
- */
-export function takeReloadBreadcrumb(): ReloadBreadcrumb | null {
-  try {
-    const raw = sessionStorage.getItem(RELOAD_BREADCRUMB_KEY);
-    if (!raw) return null;
-    sessionStorage.removeItem(RELOAD_BREADCRUMB_KEY);
-    return JSON.parse(raw) as ReloadBreadcrumb;
-  } catch {
-    return null;
-  }
-}

apps/client/vite.config.ts

@@ -1,8 +1,7 @@
-import { defineConfig, loadEnv, type Plugin } from "vite";
+import { defineConfig, loadEnv } from "vite";
 import react from "@vitejs/plugin-react";
 import { compression } from "vite-plugin-compression2";
 import * as path from "path";
-import * as fs from "node:fs";
 import { execSync } from "node:child_process";
 
 const envPath = path.resolve(process.cwd(), "..", "..");
@@ -25,32 +24,7 @@ function resolveAppVersion(cwd: string): string {
   }
 }
 
-// Emit <outDir>/version.json = { "version": appVersion } so the server can read
-// the exact same build id the bundle was compiled with. The value is the SAME
-// `appVersion` fed into `define.APP_VERSION`, so version.json and the baked-in
-// global are identical by construction — the single source of truth (no
-// runtime-env second copy that could drift and cause a false version mismatch).
-function versionJsonPlugin(version: string): Plugin {
-  let outDir = "dist";
-  return {
-    name: "emit-version-json",
-    apply: "build",
-    configResolved(config) {
-      outDir = config.build.outDir;
-    },
-    writeBundle() {
-      const root = path.resolve(process.cwd(), outDir);
-      fs.mkdirSync(root, { recursive: true });
-      fs.writeFileSync(
-        path.join(root, "version.json"),
-        JSON.stringify({ version }),
-      );
-    },
-  };
-}
-
 export default defineConfig(({ mode }) => {
-  const appVersion = resolveAppVersion(envPath);
   const {
     APP_URL,
     FILE_UPLOAD_SIZE_LIMIT,
@@ -78,11 +52,10 @@ export default defineConfig(({ mode }) => {
         POSTHOG_HOST,
         POSTHOG_KEY,
       },
-      APP_VERSION: JSON.stringify(appVersion),
+      APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
     },
     plugins: [
       react(),
-      versionJsonPlugin(appVersion),
       // Emit .br and .gz next to every built asset so the server can serve the
       // precompressed copy (see @fastify/static preCompressed in static.module.ts).
       compression({

apps/server/src/common/helpers/client-version.spec.ts

@@ -1,52 +0,0 @@
-import { join } from 'path';
-import * as fs from 'node:fs';
-import * as os from 'node:os';
-import { readClientBuildVersion } from './client-version';
-
-describe('readClientBuildVersion', () => {
-  let dir: string;
-
-  beforeEach(() => {
-    dir = fs.mkdtempSync(join(os.tmpdir(), 'client-version-'));
-  });
-
-  afterEach(() => {
-    fs.rmSync(dir, { recursive: true, force: true });
-  });
-
-  const writeVersionJson = (content: string) =>
-    fs.writeFileSync(join(dir, 'version.json'), content);
-
-  it('returns the version from a valid version.json', () => {
-    writeVersionJson(JSON.stringify({ version: 'test-A' }));
-    expect(readClientBuildVersion(dir)).toBe('test-A');
-  });
-
-  it('trims surrounding whitespace in the version', () => {
-    writeVersionJson(JSON.stringify({ version: '  v1.2.3  ' }));
-    expect(readClientBuildVersion(dir)).toBe('v1.2.3');
-  });
-
-  it('returns "" when version.json is missing', () => {
-    expect(readClientBuildVersion(dir)).toBe('');
-  });
-
-  it('returns "" on malformed JSON', () => {
-    writeVersionJson('{ not json');
-    expect(readClientBuildVersion(dir)).toBe('');
-  });
-
-  it('returns "" when the version field is absent', () => {
-    writeVersionJson(JSON.stringify({ notVersion: 'x' }));
-    expect(readClientBuildVersion(dir)).toBe('');
-  });
-
-  it('returns "" when the version field is not a string', () => {
-    writeVersionJson(JSON.stringify({ version: 123 }));
-    expect(readClientBuildVersion(dir)).toBe('');
-  });
-
-  it('returns "" when the path does not exist at all', () => {
-    expect(readClientBuildVersion(join(dir, 'nope'))).toBe('');
-  });
-});

apps/server/src/common/helpers/client-version.ts

@@ -1,36 +0,0 @@
-import { join } from 'path';
-import * as fs from 'node:fs';
-
-/**
- * Resolve the absolute path to the built client bundle directory
- * (`apps/client/dist`) shipped into the runtime image.
- *
- * The `../` depth is anchored on THIS module's compiled location
- * (`dist/common/helpers`). `integrations/static` sits at the same depth under
- * the compiled root, so both callers (StaticModule and readClientBuildVersion)
- * MUST share this single helper rather than duplicating the depth — a copy in a
- * module at a different depth would silently resolve to the wrong directory.
- */
-export function resolveClientDistPath(): string {
-  return join(__dirname, '..', '..', '..', '..', 'client/dist');
-}
-
-/**
- * Read the build version the client bundle was compiled with, from
- * `<clientDistPath>/version.json` (written by the Vite build — the single
- * source of truth shared by the baked-in `APP_VERSION` global and this file).
- *
- * Fail-safe: any error (missing file, unreadable, bad JSON, non-string
- * version) yields `''`. The caller treats an empty version as "unknown" and
- * the whole version-coherence feature stays silently inert — existing deploys
- * without the file keep working unchanged.
- */
-export function readClientBuildVersion(clientDistPath: string): string {
-  try {
-    const raw = fs.readFileSync(join(clientDistPath, 'version.json'), 'utf8');
-    const version = (JSON.parse(raw) as { version?: unknown }).version;
-    return typeof version === 'string' ? version.trim() : '';
-  } catch {
-    return '';
-  }
-}

apps/server/src/common/helpers/index.ts

@@ -3,4 +3,3 @@ export * from './nanoid.utils';
 export * from './file.helper';
 export * from './constants';
 export * from './security-headers';
-export * from './client-version';

apps/server/src/core/page/dto/page.dto.ts

@@ -5,6 +5,7 @@ import {
   IsOptional,
   IsString,
   IsUUID,
+  MaxLength,
 } from 'class-validator';
 import { Transform } from 'class-transformer';
 
@@ -47,6 +48,17 @@ export class PageInfoDto extends PageIdDto {
   format?: ContentFormat;
 }
 
+export class PageWorkTimeDto extends PageIdDto {
+  // Viewer IANA timezone for the per-day punch-card buckets (§6.3). Optional —
+  // falls back to UTC server-side. Length-capped so a bogus value cannot bloat
+  // the request; the value is only ever handed to Intl.DateTimeFormat, which
+  // throws on an unknown zone (caught by the controller → 400).
+  @IsOptional()
+  @IsString()
+  @MaxLength(64)
+  tz?: string;
+}
+
 export class DeletePageDto extends PageIdDto {
   @IsOptional()
   @IsBoolean()

apps/server/src/core/page/page.controller.spec.ts

@@ -1,3 +1,8 @@
+import {
+  BadRequestException,
+  ForbiddenException,
+  NotFoundException,
+} from '@nestjs/common';
 import { PageController } from './page.controller';
 
 // Direct instantiation with stub deps. The Test.createTestingModule form failed
@@ -22,4 +27,88 @@ describe('PageController', () => {
   it('should be defined', () => {
     expect(controller).toBeDefined();
   });
+
+  // #395 — the work-time endpoint must be gated exactly like /history.
+  describe('getPageWorkTime', () => {
+    const user = { id: 'u1' } as any;
+
+    function build(overrides: {
+      page?: any;
+      validate?: jest.Mock;
+      compute?: jest.Mock;
+    }) {
+      const pageRepo = { findById: jest.fn().mockResolvedValue(overrides.page) };
+      const pageAccessService = {
+        validateCanView: overrides.validate ?? jest.fn().mockResolvedValue(undefined),
+      };
+      const pageHistoryService = {
+        computeWorkTime:
+          overrides.compute ?? jest.fn().mockResolvedValue({ workMs: 0 }),
+      };
+      const c = new PageController(
+        {} as any,
+        pageRepo as any,
+        pageHistoryService as any,
+        {} as any,
+        pageAccessService as any,
+        {} as any,
+        {} as any,
+        {} as any,
+      );
+      return { c, pageRepo, pageAccessService, pageHistoryService };
+    }
+
+    it('404s when the page does not exist', async () => {
+      const { c } = build({ page: null });
+      await expect(
+        c.getPageWorkTime({ pageId: 'p1' } as any, user),
+      ).rejects.toBeInstanceOf(NotFoundException);
+    });
+
+    it('enforces validateCanView before computing, then delegates with tz', async () => {
+      const validate = jest.fn().mockResolvedValue(undefined);
+      const compute = jest.fn().mockResolvedValue({ workMs: 42 });
+      const { c } = build({ page: { id: 'pg' }, validate, compute });
+      const out = await c.getPageWorkTime(
+        { pageId: 'pg', tz: 'Europe/Moscow' } as any,
+        user,
+      );
+      expect(validate).toHaveBeenCalledWith({ id: 'pg' }, user);
+      expect(compute).toHaveBeenCalledWith('pg', 'Europe/Moscow');
+      expect(out).toEqual({ workMs: 42 });
+    });
+
+    it('propagates a denied view gate and does NOT reach compute (security)', async () => {
+      // If validateCanView is moved AFTER computeWorkTime, the timeline of a page
+      // the caller may not see would be read/estimated before the gate — this
+      // locks the order: a rejecting gate must short-circuit before any compute.
+      const validate = jest.fn().mockRejectedValue(new ForbiddenException());
+      const compute = jest.fn().mockResolvedValue({ workMs: 1 });
+      const { c, pageHistoryService } = build({
+        page: { id: 'pg' },
+        validate,
+        compute,
+      });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg' } as any, user),
+      ).rejects.toBeInstanceOf(ForbiddenException);
+      expect(pageHistoryService.computeWorkTime).not.toHaveBeenCalled();
+    });
+
+    it('maps an unknown-timezone RangeError to a 400', async () => {
+      const compute = jest.fn().mockRejectedValue(new RangeError('bad tz'));
+      const { c } = build({ page: { id: 'pg' }, compute });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg', tz: 'X/Y' } as any, user),
+      ).rejects.toBeInstanceOf(BadRequestException);
+    });
+
+    it('does not swallow a non-RangeError from the service', async () => {
+      const compute = jest.fn().mockRejectedValue(new Error('db down'));
+      const { c } = build({ page: { id: 'pg' }, compute });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg' } as any, user),
+      ).rejects.toThrow('db down');
+    });
+  });
 });

apps/server/src/core/page/page.controller.ts

@@ -21,6 +21,7 @@ import {
   PageHistoryIdDto,
   PageIdDto,
   PageInfoDto,
+  PageWorkTimeDto,
 } from './dto/page.dto';
 import { PageHistoryService } from './services/page-history.service';
 import { AuthUser } from '../../common/decorators/auth-user.decorator';
@@ -524,6 +525,32 @@ export class PageController {
     return this.pageHistoryService.findHistoryByPageId(page.id, pagination);
   }
 
+  @HttpCode(HttpStatus.OK)
+  @Post('/history/time')
+  async getPageWorkTime(
+    @Body() dto: PageWorkTimeDto,
+    @AuthUser() user: User,
+  ) {
+    const page = await this.pageRepo.findById(dto.pageId);
+    if (!page) {
+      throw new NotFoundException('Page not found');
+    }
+
+    // Same view gate as /history and /history/info.
+    await this.pageAccessService.validateCanView(page, user);
+
+    try {
+      return await this.pageHistoryService.computeWorkTime(page.id, dto.tz);
+    } catch (e) {
+      // Intl.DateTimeFormat throws RangeError on an unknown IANA zone; surface
+      // it as a 400 rather than a 500.
+      if (e instanceof RangeError) {
+        throw new BadRequestException('Invalid timezone');
+      }
+      throw e;
+    }
+  }
+
   @HttpCode(HttpStatus.OK)
   @Post('/history/info')
   async getPageHistoryInfo(

apps/server/src/core/page/services/page-history.service.ts

@@ -3,6 +3,23 @@ import { PageHistoryRepo } from '@docmost/db/repos/page/page-history.repo';
 import { PageHistory } from '@docmost/db/types/entity.types';
 import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
 import { CursorPaginationResult } from '@docmost/db/pagination/cursor-pagination';
+import {
+  computeWorkTime,
+  bucketByDay,
+  DEFAULT_WORK_TIME_CONFIG,
+  WorkTimeConfig,
+  PerDay,
+} from '../work-time';
+
+export interface PageWorkTime {
+  workMs: number;
+  agentOnlyMs: number;
+  perDay: PerDay[];
+  /** the config actually used, so the UI can show "≈" + the T_gap threshold. */
+  config: WorkTimeConfig;
+  /** the tz the per-day buckets were computed in (echoed back for the label). */
+  tz: string;
+}
 
 @Injectable()
 export class PageHistoryService {
@@ -23,4 +40,33 @@ export class PageHistoryService {
       paginationOptions,
     );
   }
+
+  /**
+   * #395 — estimate time worked on a page (§5) and bucket it into the viewer's
+   * calendar days for the punch-card (§6.3). Reads only the cheap history
+   * projection (no `content`); the estimate itself is a pure, deterministic
+   * function so it is unit-tested exhaustively without a DB.
+   *
+   * `tz` is the viewer's IANA zone (browser locale) — it moves which day a
+   * session lands in and where its windows sit, but never the total (§10).
+   */
+  async computeWorkTime(
+    pageId: string,
+    tz = 'UTC',
+    config?: Partial<WorkTimeConfig>,
+  ): Promise<PageWorkTime> {
+    const rows = await this.pageHistoryRepo.findTimelineByPageId(pageId);
+    const result = computeWorkTime(rows, config);
+    const usedConfig: WorkTimeConfig = { ...DEFAULT_WORK_TIME_CONFIG, ...config };
+    // `bucketByDay` consumes the pure core's un-bucketed sessions here; the
+    // full session list is NOT shipped on the response (no client reads it).
+    const perDay = bucketByDay(result.sessions, tz);
+    return {
+      workMs: result.workMs,
+      agentOnlyMs: result.agentOnlyMs,
+      perDay,
+      config: usedConfig,
+      tz,
+    };
+  }
 }

apps/server/src/core/page/work-time/bucket-by-day.spec.ts

@@ -0,0 +1,129 @@
+import { bucketByDay, zonedDayStart } from './bucket-by-day';
+import { computeWorkTime } from './compute-work-time';
+import { WorkSession, TimelineSample } from './work-time.types';
+
+const MIN = 60 * 1000;
+const HOUR = 60 * MIN;
+
+function work(start: number, end: number): WorkSession {
+  return { start, end, class: 'work' };
+}
+function agent(start: number, end: number): WorkSession {
+  return { start, end, class: 'agent_only' };
+}
+
+function sumActive(perDay: ReturnType<typeof bucketByDay>): number {
+  return perDay.reduce((a, d) => a + d.activeMs, 0);
+}
+
+describe('bucketByDay', () => {
+  it('Σ activeMs == workMs — the §6.3 consistency invariant', () => {
+    const rows: TimelineSample[] = [
+      { createdAt: '2026-07-04T03:40:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-04T03:49:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-04T18:11:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-06T15:34:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+    ];
+    const r = computeWorkTime(rows);
+    const perDay = bucketByDay(r.sessions, 'UTC');
+    expect(sumActive(perDay)).toBe(r.workMs);
+  });
+
+  it('empty input → no days', () => {
+    expect(bucketByDay([], 'UTC')).toEqual([]);
+  });
+
+  it('midnight-crossing session splits across two days, sum preserved (§9#9)', () => {
+    const start = Date.UTC(2026, 0, 10, 23, 14);
+    const end = Date.UTC(2026, 0, 11, 0, 40);
+    const perDay = bucketByDay([work(start, end)], 'UTC');
+    expect(perDay).toHaveLength(2);
+    expect(perDay[0].dayISO).toBe('2026-01-10');
+    expect(perDay[1].dayISO).toBe('2026-01-11');
+    expect(perDay[0].activeMs).toBe(46 * MIN); // 23:14 → 24:00
+    expect(perDay[1].activeMs).toBe(40 * MIN); // 00:00 → 00:40
+    expect(sumActive(perDay)).toBe(end - start);
+  });
+
+  it('empty days between active days are emitted, not skipped (§9#12)', () => {
+    const d1 = work(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const d3 = work(Date.UTC(2026, 0, 12, 10, 0), Date.UTC(2026, 0, 12, 11, 0));
+    const perDay = bucketByDay([d1, d3], 'UTC');
+    expect(perDay.map((d) => d.dayISO)).toEqual([
+      '2026-01-10',
+      '2026-01-11',
+      '2026-01-12',
+    ]);
+    expect(perDay[1].activeMs).toBe(0);
+    expect(perDay[1].windows).toEqual([]);
+  });
+
+  it('agent_only windows are drawn but excluded from activeMs', () => {
+    const w = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 10, 0));
+    const a = agent(Date.UTC(2026, 0, 10, 14, 0), Date.UTC(2026, 0, 10, 14, 30));
+    const perDay = bucketByDay([w, a], 'UTC');
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].activeMs).toBe(1 * HOUR);
+    expect(perDay[0].agentMs).toBe(30 * MIN);
+    expect(perDay[0].windows.map((x) => x.class)).toEqual(['work', 'agent_only']);
+  });
+
+  it('work and agent_only are unioned SEPARATELY (agent does not swallow work)', () => {
+    // Overlapping work + agent windows on the same day.
+    const w = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const a = agent(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 12, 0));
+    const perDay = bucketByDay([w, a], 'UTC');
+    expect(perDay[0].activeMs).toBe(2 * HOUR);
+    expect(perDay[0].agentMs).toBe(2 * HOUR);
+  });
+
+  it('overlapping same-class sessions are UNIONed, not summed (no double-count)', () => {
+    // Two work sessions that overlap 10:00–10:30 on one day.
+    const a = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 10, 30));
+    const b = work(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const perDay = bucketByDay([a, b], 'UTC');
+    expect(perDay).toHaveLength(1);
+    // Union 09:00–11:00 = 2h, NOT 90m + 60m = 150m.
+    expect(perDay[0].activeMs).toBe(2 * HOUR);
+    // The drawn windows are also merged to one, so the punch-card cannot render
+    // an overlapping double bar.
+    expect(perDay[0].windows).toHaveLength(1);
+    expect(perDay[0].windows[0].start).toBe(a.start);
+    expect(perDay[0].windows[0].end).toBe(b.end);
+  });
+
+  it('DST fall-back: a full 25-hour day still balances (§9#14)', () => {
+    // America/New_York ends DST 2026-11-01 (25h day).
+    const tz = 'America/New_York';
+    const dayStart = zonedDayStart(Date.UTC(2026, 10, 1, 12, 0), tz);
+    const nextStart = zonedDayStart(dayStart + 26 * HOUR, tz);
+    expect(nextStart - dayStart).toBe(25 * HOUR);
+    const perDay = bucketByDay([work(dayStart, nextStart)], tz);
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].dayISO).toBe('2026-11-01');
+    expect(perDay[0].activeMs).toBe(25 * HOUR);
+    expect(sumActive(perDay)).toBe(nextStart - dayStart);
+  });
+
+  it('DST spring-forward: a full 23-hour day still balances (§9#14)', () => {
+    // America/New_York starts DST 2026-03-08 (23h day).
+    const tz = 'America/New_York';
+    const dayStart = zonedDayStart(Date.UTC(2026, 2, 8, 12, 0), tz);
+    const nextStart = zonedDayStart(dayStart + 26 * HOUR, tz);
+    expect(nextStart - dayStart).toBe(23 * HOUR);
+    const perDay = bucketByDay([work(dayStart, nextStart)], tz);
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].activeMs).toBe(23 * HOUR);
+    expect(sumActive(perDay)).toBe(nextStart - dayStart);
+  });
+
+  it('tz changes the day a session lands in but not the total', () => {
+    const start = Date.UTC(2026, 0, 10, 2, 0); // 02:00 UTC
+    const end = Date.UTC(2026, 0, 10, 3, 0);
+    const utc = bucketByDay([work(start, end)], 'UTC');
+    const ny = bucketByDay([work(start, end)], 'America/New_York'); // 21:00 prev day
+    expect(utc[0].dayISO).toBe('2026-01-10');
+    expect(ny[0].dayISO).toBe('2026-01-09');
+    expect(sumActive(utc)).toBe(sumActive(ny));
+  });
+});

apps/server/src/core/page/work-time/bucket-by-day.ts

@@ -0,0 +1,180 @@
+import { WorkSession, PerDay, DayWindow } from './work-time.types';
+
+/**
+ * Merge intervals into a disjoint, sorted union. Overlapping OR touching
+ * intervals are joined. Empty input → [].
+ */
+function union(intervals: Array<[number, number]>): Array<[number, number]> {
+  if (intervals.length === 0) return [];
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  const out: Array<[number, number]> = [];
+  let [curStart, curEnd] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= curEnd) {
+      if (e > curEnd) curEnd = e;
+    } else {
+      out.push([curStart, curEnd]);
+      curStart = s;
+      curEnd = e;
+    }
+  }
+  out.push([curStart, curEnd]);
+  return out;
+}
+
+// Cache one Intl formatter per tz — constructing them is comparatively costly.
+const fmtCache = new Map<string, Intl.DateTimeFormat>();
+
+function partsFmt(tz: string): Intl.DateTimeFormat {
+  let fmt = fmtCache.get(tz);
+  if (!fmt) {
+    fmt = new Intl.DateTimeFormat('en-US', {
+      timeZone: tz,
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit',
+      hour: '2-digit',
+      minute: '2-digit',
+      second: '2-digit',
+      hour12: false,
+    });
+    fmtCache.set(tz, fmt);
+  }
+  return fmt;
+}
+
+interface WallParts {
+  year: number;
+  month: number;
+  day: number;
+  hour: number;
+  minute: number;
+  second: number;
+}
+
+/** Wall-clock parts of an instant in `tz` (DST-correct, via Intl). */
+function wallParts(ms: number, tz: string): WallParts {
+  const parts = partsFmt(tz).formatToParts(new Date(ms));
+  const get = (type: string) =>
+    Number(parts.find((p) => p.type === type)?.value ?? '0');
+  let hour = get('hour');
+  // Intl emits "24" for midnight under some engines/locales; normalize to 0.
+  if (hour === 24) hour = 0;
+  return {
+    year: get('year'),
+    month: get('month'),
+    day: get('day'),
+    hour,
+    minute: get('minute'),
+    second: get('second'),
+  };
+}
+
+/** tz offset (wall − real) at an instant, in ms. */
+function offset(ms: number, tz: string): number {
+  const p = wallParts(ms, tz);
+  const asUTC = Date.UTC(p.year, p.month - 1, p.day, p.hour, p.minute, p.second);
+  return asUTC - ms;
+}
+
+/**
+ * Epoch-ms of the local-midnight day start of `ms` in `tz`. DST-correct: takes
+ * the calendar day of the instant, its wall-midnight, then converts back with
+ * the offset that actually applies AT that midnight (refined once). The rare
+ * tz-with-a-DST-transition-exactly-at-midnight case is a documented edge (§9#14).
+ */
+export function zonedDayStart(ms: number, tz: string): number {
+  const p = wallParts(ms, tz);
+  const wallMidnightAsUTC = Date.UTC(p.year, p.month - 1, p.day, 0, 0, 0);
+  let start = wallMidnightAsUTC - offset(ms, tz);
+  // Refine with the offset at the computed midnight (DST may differ from `ms`).
+  start = wallMidnightAsUTC - offset(start, tz);
+  return start;
+}
+
+/** The next local midnight after `dayStart` (handles 23/25h DST days). */
+function nextDayStart(dayStart: number, tz: string): number {
+  // +26h always lands inside the NEXT calendar day (day length ∈ [23h,25h]),
+  // never two days ahead; startOf('day') of it is the next midnight.
+  return zonedDayStart(dayStart + 26 * 60 * 60 * 1000, tz);
+}
+
+function isoDay(dayStart: number, tz: string): string {
+  const p = wallParts(dayStart, tz);
+  const pad = (n: number) => String(n).padStart(2, '0');
+  return `${p.year}-${pad(p.month)}-${pad(p.day)}`;
+}
+
+/** Clip a union to [lo, hi) and emit windows of `class`. */
+function clip(
+  merged: Array<[number, number]>,
+  lo: number,
+  hi: number,
+  cls: DayWindow['class'],
+): DayWindow[] {
+  const out: DayWindow[] = [];
+  for (const [s, e] of merged) {
+    const start = Math.max(s, lo);
+    const end = Math.min(e, hi);
+    if (end > start) out.push({ start, end, class: cls });
+  }
+  return out;
+}
+
+/**
+ * #395 §6.3 — bucket sessions into calendar days of `tz` for the punch-card.
+ * Pure and deterministic. `work` and `agent_only` are unioned SEPARATELY (else
+ * agent windows would swallow work windows on overlap), then each union is split
+ * at tz midnight boundaries (`startOf('day')` in tz, NOT "+24h" — DST-safe §9#14)
+ * and clipped to each day.
+ *
+ * By construction Σ perDay.activeMs == workMs: the days are a partition of the
+ * `work` union — no loss, no dup, even on 23/25h DST days. `agent_only` windows
+ * are drawn but NOT in activeMs. Empty days between the first and last active day
+ * are emitted (empty track + "—") so the rhythm/pauses stay visible.
+ */
+export function bucketByDay(sessions: WorkSession[], tz: string): PerDay[] {
+  const uWork = union(
+    sessions.filter((s) => s.class === 'work').map((s) => [s.start, s.end]),
+  );
+  const uAgent = union(
+    sessions
+      .filter((s) => s.class === 'agent_only')
+      .map((s) => [s.start, s.end]),
+  );
+
+  if (uWork.length === 0 && uAgent.length === 0) return [];
+
+  const minStart = Math.min(
+    uWork.length ? uWork[0][0] : Infinity,
+    uAgent.length ? uAgent[0][0] : Infinity,
+  );
+  const maxEnd = Math.max(
+    uWork.length ? uWork[uWork.length - 1][1] : -Infinity,
+    uAgent.length ? uAgent[uAgent.length - 1][1] : -Infinity,
+  );
+
+  const perDay: PerDay[] = [];
+  let dayStart = zonedDayStart(minStart, tz);
+  // Guard against a pathological non-advancing boundary.
+  let guard = 0;
+  while (dayStart < maxEnd && guard < 100000) {
+    guard++;
+    const dayEnd = nextDayStart(dayStart, tz);
+    const workWin = clip(uWork, dayStart, dayEnd, 'work');
+    const agentWin = clip(uAgent, dayStart, dayEnd, 'agent_only');
+    const activeMs = workWin.reduce((a, w) => a + (w.end - w.start), 0);
+    const agentMs = agentWin.reduce((a, w) => a + (w.end - w.start), 0);
+    const windows = [...workWin, ...agentWin].sort((a, b) => a.start - b.start);
+    perDay.push({
+      day: dayStart,
+      dayISO: isoDay(dayStart, tz),
+      activeMs,
+      agentMs,
+      windows,
+    });
+    dayStart = dayEnd;
+  }
+  return perDay;
+}

apps/server/src/core/page/work-time/compute-work-time.spec.ts

@@ -0,0 +1,358 @@
+import { computeWorkTime } from './compute-work-time';
+import { bucketByDay } from './bucket-by-day';
+import { TimelineSample, WorkSession } from './work-time.types';
+
+const MIN = 60 * 1000;
+
+/** Union wall-clock of a set of intervals (touching intervals merge). */
+function unionMs(intervals: Array<[number, number]>): number {
+  if (intervals.length === 0) return 0;
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  let total = 0;
+  let [cs, ce] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= ce) {
+      if (e > ce) ce = e;
+    } else {
+      total += ce - cs;
+      cs = s;
+      ce = e;
+    }
+  }
+  return total + (ce - cs);
+}
+
+const ivsOf = (sessions: WorkSession[], cls?: string): Array<[number, number]> =>
+  sessions
+    .filter((x) => cls == null || x.class === cls)
+    .map((x) => [x.start, x.end] as [number, number]);
+
+function s(
+  iso: string,
+  opts: {
+    source?: string | null;
+    chat?: string | null;
+    kind?: string | null;
+    by?: string | null;
+  } = {},
+): TimelineSample {
+  return {
+    createdAt: `${iso}Z`,
+    lastUpdatedById: opts.by ?? 'human-1',
+    lastUpdatedSource: opts.source === undefined ? 'user' : opts.source,
+    lastUpdatedAiChatId: opts.chat ?? null,
+    kind: opts.kind ?? null,
+  };
+}
+
+// §7 config: T_gap=30m, P_in+P_out=10m, P_single=2m.
+const S7 = { tGap: 30 * MIN, agentTGap: 30 * MIN, pIn: 5 * MIN, pOut: 5 * MIN, pSingle: 2 * MIN };
+
+describe('computeWorkTime', () => {
+  it('§7 fixture — sessionizes 20-ish samples to ≈1h32m, not the ≈60h naive span', () => {
+    const rows: TimelineSample[] = [
+      // S1: multi-sample morning session
+      s('2026-07-04T03:40:00'),
+      s('2026-07-04T03:45:00'),
+      s('2026-07-04T03:49:00'),
+      // S2: agent burst (one run) then human supervising → class work
+      s('2026-07-04T15:43:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T15:47:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T15:50:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T16:13:00'),
+      // S3: single
+      s('2026-07-04T18:11:00'),
+      // S4: multi-sample evening session
+      s('2026-07-04T19:38:00'),
+      s('2026-07-04T19:44:00'),
+      s('2026-07-04T19:54:00'),
+      // S5 / S6: two singles two days later, 44m apart → two sessions at T_gap=30
+      s('2026-07-06T15:34:00'),
+      s('2026-07-06T16:18:00'),
+    ];
+
+    const r = computeWorkTime(rows, S7);
+
+    // 19 + 40 + 2 + 26 + 2 + 2 = 91 minutes.
+    expect(r.workMs).toBe(91 * MIN);
+    expect(r.agentOnlyMs).toBe(0);
+    expect(r.sessions).toHaveLength(6);
+    expect(r.sessions.every((x) => x.class === 'work')).toBe(true);
+
+    const naiveSpan =
+      new Date('2026-07-06T16:18:00Z').getTime() -
+      new Date('2026-07-04T03:40:00Z').getTime();
+    expect(naiveSpan).toBeGreaterThan(60 * 60 * MIN); // ≈60h
+    expect(r.workMs).toBeLessThan(naiveSpan / 30); // dramatically smaller
+  });
+
+  it('n=0 → zero, no sessions', () => {
+    const r = computeWorkTime([]);
+    expect(r).toEqual({ workMs: 0, agentOnlyMs: 0, sessions: [] });
+  });
+
+  it('n=1 human → one P_single work session', () => {
+    const r = computeWorkTime([s('2026-07-04T10:00:00')], S7);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.workMs).toBe(2 * MIN);
+    expect(r.agentOnlyMs).toBe(0);
+    // pre-roll only: [t − P_single, t]
+    expect(r.sessions[0].end).toBe(new Date('2026-07-04T10:00:00Z').getTime());
+  });
+
+  it('n=1 agent → one P_single agent_only session, work=0 (§9#2)', () => {
+    const r = computeWorkTime(
+      [s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' })],
+      S7,
+    );
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('agent_only');
+    expect(r.workMs).toBe(0);
+    expect(r.agentOnlyMs).toBe(2 * MIN);
+  });
+
+  it('MUST close the last session — the newest session is not lost (§9#1)', () => {
+    // Two singles a day apart: without the post-loop close, the 2nd is dropped.
+    const rows = [s('2026-07-04T10:00:00'), s('2026-07-05T10:00:00')];
+    const r = computeWorkTime(rows, S7);
+    expect(r.sessions).toHaveLength(2);
+    const lastStart = Math.max(...r.sessions.map((x) => x.start));
+    expect(lastStart).toBe(
+      new Date('2026-07-05T10:00:00Z').getTime() - 2 * MIN,
+    );
+    expect(r.workMs).toBe(4 * MIN);
+  });
+
+  it('agent-burst collapse: density does not inflate — length = wall-clock', () => {
+    const span = ['00', '01', '02', '03', '04', '05', '06'];
+    const dense: TimelineSample[] = span.map((sec) =>
+      s(`2026-07-04T10:00:${sec}`, { source: 'agent', chat: 'c1', kind: 'agent' }),
+    );
+    const sparse: TimelineSample[] = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:00:06', { source: 'agent', chat: 'c1', kind: 'agent' }),
+    ];
+    const rDense = computeWorkTime(dense, S7);
+    const rSparse = computeWorkTime(sparse, S7);
+    // Same 6-second wall-clock span → same estimate regardless of snapshot count.
+    expect(rDense.agentOnlyMs).toBe(rSparse.agentOnlyMs);
+    expect(rDense.sessions).toHaveLength(1);
+    expect(rDense.sessions[0].class).toBe('agent_only');
+  });
+
+  it('supervisory agent time inside a human session counts as work, not agent', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:05:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:12:00'), // human within T_gap
+    ];
+    const r = computeWorkTime(rows, S7);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.agentOnlyMs).toBe(0);
+    expect(r.workMs).toBeGreaterThan(0);
+  });
+
+  it('a DIFFERENT aiChatId breaks the burst — two agent runs, idle gap excluded', () => {
+    // Run c1 ends 10:05, run c2 starts 10:20 (15m > agentTGap 7m) → two sessions.
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:05:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:20:00', { source: 'agent', chat: 'c2', kind: 'agent' }),
+      s('2026-07-04T10:25:00', { source: 'agent', chat: 'c2', kind: 'agent' }),
+    ];
+    const r = computeWorkTime(rows); // default agentTGap = 7m
+    expect(r.sessions).toHaveLength(2);
+    expect(r.sessions.every((x) => x.class === 'agent_only')).toBe(true);
+    // The 15m idle gap between the two runs is NOT counted.
+    const run1 = 5 * MIN + 5 * MIN + 5 * MIN; // pIn + span + pOut
+    expect(r.agentOnlyMs).toBe(2 * run1);
+  });
+
+  it('idle pulse (same/null run) is a full activity sample that continues a burst', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      // idle flush 4m later, null run id → continues the burst, not a new one
+      s('2026-07-04T10:04:00', { source: 'agent', chat: null, kind: 'idle' }),
+      s('2026-07-04T10:08:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    // burst span 10:00→10:08 (+pIn/pOut) = 8 + 10 = 18m
+    expect(r.agentOnlyMs).toBe(18 * MIN);
+  });
+
+  it('a USER-sourced idle breaks an agent burst → session is work, not agent_only', () => {
+    // A human supervision idle inherits source=user (aiChatId:null) and must NOT
+    // be swallowed into the agent burst. Δ=3m is within the default agentTGap so
+    // the two samples stay one session — but its class flips to `work`.
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:03:00', { source: 'user', chat: null, kind: 'idle' }),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.workMs).toBeGreaterThan(0);
+    // The human idle is NOT captured as agent_only time.
+    expect(r.agentOnlyMs).toBe(0);
+    // Σ over `work` sessions == workMs and Σ over `agent_only` == agentOnlyMs.
+    const sum = (cls: string) =>
+      r.sessions
+        .filter((x) => x.class === cls)
+        .reduce((acc, x) => acc + (x.end - x.start), 0);
+    expect(sum('work')).toBe(r.workMs);
+    expect(sum('agent_only')).toBe(r.agentOnlyMs);
+  });
+
+  it('idle pulse keeps a human writing session visible (not excluded)', () => {
+    const rows = [
+      s('2026-07-04T10:00:00'),
+      s('2026-07-04T10:08:00', { kind: 'idle' }), // pulse within T_gap
+      s('2026-07-04T10:15:00'),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    // span 10:00→10:15 + pIn/pOut = 15 + 10 = 25m
+    expect(r.workMs).toBe(25 * MIN);
+  });
+
+  it('git-source samples are excluded (§10 excludeGit)', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'git', kind: 'boundary' }),
+      s('2026-07-04T10:01:00', { source: 'git', kind: 'boundary' }),
+    ];
+    expect(computeWorkTime(rows).workMs).toBe(0);
+    // ...but honoured off:
+    expect(
+      computeWorkTime(rows, { excludeGit: false }).workMs,
+    ).toBeGreaterThan(0);
+  });
+
+  it('rejects an invalid config (tGap < pIn + pOut)', () => {
+    expect(() =>
+      computeWorkTime([s('2026-07-04T10:00:00')], {
+        tGap: 5 * MIN,
+        pIn: 5 * MIN,
+        pOut: 5 * MIN,
+      }),
+    ).toThrow(/tGap/);
+  });
+
+  it('rejects an invalid config (2·agentTGap < pIn + pOut)', () => {
+    // tGap (default 15m) still ≥ pIn+pOut, so only the 2·agentTGap guard trips.
+    // Without it a short session of one class between two of the other could
+    // produce a NON-adjacent cross-class overlap the adjacent-only clip misses.
+    expect(() =>
+      computeWorkTime([s('2026-07-04T10:00:00')], {
+        agentTGap: 2 * MIN,
+        pIn: 5 * MIN,
+        pOut: 5 * MIN,
+      }),
+    ).toThrow(/agentTGap/);
+  });
+
+  // F1 — cross-class double-count. On the DEFAULT config agentTGap (7m) < pIn+pOut
+  // (10m), so a `work` session ending in an agent segment and a nearby separate
+  // `agent_only` run (gap in (7m,10m]) used to produce OVERLAPPING padded
+  // intervals — the same wall-clock counted into BOTH workMs and agentOnlyMs. The
+  // cross-class padding clip must make the two per-class unions disjoint.
+  it('does NOT double-count wall-clock across work/agent_only (§F1)', () => {
+    // user@0s ; agent(chatX)@60s (breaks into a work session with the human) ;
+    // agent(chatY)@560s,590s (a separate agent_only run). Raw gap between the work
+    // session (ends 60s) and the agent run (starts 560s) is 500s ∈ (agentTGap,
+    // pIn+pOut] once padded — the classic overlap window.
+    const rows: TimelineSample[] = [
+      s('2026-07-04T00:00:00'), // user @ 0s
+      s('2026-07-04T00:01:00', { source: 'agent', chat: 'cX', kind: 'agent' }), // @ 60s
+      s('2026-07-04T00:09:20', { source: 'agent', chat: 'cY', kind: 'agent' }), // @ 560s
+      s('2026-07-04T00:09:50', { source: 'agent', chat: 'cY', kind: 'agent' }), // @ 590s
+    ];
+    const r = computeWorkTime(rows); // DEFAULT config
+
+    // Both classes present.
+    expect(r.workMs).toBeGreaterThan(0);
+    expect(r.agentOnlyMs).toBeGreaterThan(0);
+
+    // Per-class metrics are exactly their own union (union, not Σ).
+    expect(r.workMs).toBe(unionMs(ivsOf(r.sessions, 'work')));
+    expect(r.agentOnlyMs).toBe(unionMs(ivsOf(r.sessions, 'agent_only')));
+
+    // The F1 invariant: work-union and agent-union are cross-class-disjoint, so
+    // the union of ALL padded intervals equals workMs + agentOnlyMs (no overlap).
+    // With the clip disabled this fails (union < sum by the 100s overlap).
+    expect(unionMs(ivsOf(r.sessions))).toBe(r.workMs + r.agentOnlyMs);
+  });
+
+  // F1 property/fuzz — random timelines across several timezones must uphold the
+  // work-time invariants. Backs the (corrected) PR claim of a real fuzz test.
+  it('property: random timelines uphold union & cross-class-disjoint invariants', () => {
+    // Deterministic LCG (numerical-recipes constants) so a failure is reproducible.
+    let seed = 0x9e3779b9 >>> 0;
+    const rand = () => {
+      seed = (Math.imul(seed, 1664525) + 1013904223) >>> 0;
+      return seed / 0x100000000;
+    };
+    const pick = <T>(arr: T[]): T => arr[Math.floor(rand() * arr.length)];
+
+    const tzs = [
+      'UTC',
+      'America/New_York',
+      'Europe/Moscow',
+      'Australia/Lord_Howe', // 30-min DST offset — a nasty bucket stress
+    ];
+    const base = Date.UTC(2026, 5, 1, 0, 0, 0); // 2026-06-01Z
+    const chats = ['c1', 'c2', 'c3'];
+
+    for (let iter = 0; iter < 250; iter++) {
+      const tz = pick(tzs);
+      const n = 2 + Math.floor(rand() * 18); // 2..19 rows
+      const rows: TimelineSample[] = [];
+      // Walk time forward by a random inter-sample gap. The gap distribution is
+      // centred on the DANGEROUS band — a bit under to a bit over pIn+pOut (10m)
+      // AND straddling agentTGap (7m) — so adjacent samples routinely split into
+      // separate sessions whose ±P padding would overlap if a class boundary sits
+      // there. Mixing user/agent classes at these gaps reliably manufactures the
+      // work-ending-in-agent → agent_only cross-class boundary F1 is about, plus
+      // dense within-class runs (occasional 0–2m gaps) that exercise the union.
+      let t = base + Math.floor(rand() * 60 * MIN);
+      for (let i = 0; i < n; i++) {
+        const roll = rand();
+        const gap =
+          roll < 0.25
+            ? Math.floor(rand() * 2 * MIN) // dense burst (same-class union)
+            : roll < 0.85
+              ? 5 * MIN + Math.floor(rand() * 8 * MIN) // 5–13m: the split band
+              : 20 * MIN + Math.floor(rand() * 40 * MIN); // long idle → new day-ish
+        t += gap;
+        const iso = new Date(t).toISOString().slice(0, 19); // 'YYYY-MM-DDTHH:MM:SS'
+        const isAgent = rand() < 0.5;
+        rows.push(
+          isAgent
+            ? s(iso, { source: 'agent', chat: pick(chats), kind: 'agent' })
+            : s(iso, { source: 'user', kind: rand() < 0.3 ? 'idle' : 'manual' }),
+        );
+      }
+
+      const r = computeWorkTime(rows); // DEFAULT config
+
+      const workIvs = ivsOf(r.sessions, 'work');
+      const agentIvs = ivsOf(r.sessions, 'agent_only');
+
+      // (1) each metric is exactly its per-class union (catches a union→Σ regress).
+      expect(r.workMs).toBe(unionMs(workIvs));
+      expect(r.agentOnlyMs).toBe(unionMs(agentIvs));
+
+      // (2) NO cross-class overlap: union(all) == workMs + agentOnlyMs (F1).
+      expect(unionMs(ivsOf(r.sessions))).toBe(r.workMs + r.agentOnlyMs);
+
+      // (3) bucket invariant: Σ per-day activeMs == workMs (§6.3).
+      const perDay = bucketByDay(r.sessions, tz);
+      const sumActive = perDay.reduce((a, d) => a + d.activeMs, 0);
+      expect(sumActive).toBe(r.workMs);
+    }
+  });
+});

apps/server/src/core/page/work-time/compute-work-time.ts

@@ -0,0 +1,274 @@
+import {
+  TimelineSample,
+  WorkSession,
+  WorkTimeResult,
+} from './work-time.types';
+import { WorkTimeConfig, resolveWorkTimeConfig } from './work-time.config';
+
+/** A normalized activity sample (one history row), createdAt as epoch-ms. */
+interface NormSample {
+  t: number;
+  isAgent: boolean;
+  aiChatId: string | null;
+  kind: string | null;
+}
+
+/**
+ * A collapsed segment: either a scalar sample (t_start == t_end) or an
+ * agent-burst spanning several agent samples of one run (§5.1). It participates
+ * in sessionization as a single "sample".
+ */
+interface Segment {
+  tStart: number;
+  tEnd: number;
+  isAgent: boolean;
+}
+
+function toMs(v: Date | string | number): number {
+  if (v instanceof Date) return v.getTime();
+  if (typeof v === 'number') return v;
+  return new Date(v).getTime();
+}
+
+/**
+ * Normalize raw rows → sorted, deduped activity samples. `git` is dropped when
+ * configured; every other kind (incl. `idle` — the continuous-work pulse §3) is
+ * a real activity sample. Sort is by createdAt ASC; samples whose timestamps
+ * fall in the same `dedupRoundMs` bucket collapse to one (§9#7: a synchronous
+ * boundary row + the immediate agent snapshot can share a createdAt). A merged
+ * sample is human unless EVERY member is an agent, so supervision never gets
+ * mis-attributed to the agent.
+ */
+function normalize(
+  rows: TimelineSample[],
+  config: WorkTimeConfig,
+): NormSample[] {
+  const samples: NormSample[] = [];
+  for (const row of rows) {
+    const source = row.lastUpdatedSource;
+    if (config.excludeGit && source === 'git') continue;
+    samples.push({
+      t: toMs(row.createdAt),
+      isAgent: source === 'agent',
+      aiChatId: row.lastUpdatedAiChatId ?? null,
+      kind: row.kind ?? null,
+    });
+  }
+  samples.sort((a, b) => a.t - b.t);
+
+  if (config.dedupRoundMs <= 0 || samples.length < 2) return samples;
+
+  const deduped: NormSample[] = [];
+  for (const s of samples) {
+    const prev = deduped[deduped.length - 1];
+    if (prev && s.t - prev.t < config.dedupRoundMs) {
+      // Merge into the previous sample. Human wins the class; keep the earliest
+      // t; keep a non-null aiChatId if either has one (so a bare boundary row
+      // does not erase the run id).
+      prev.isAgent = prev.isAgent && s.isAgent;
+      prev.aiChatId = prev.aiChatId ?? s.aiChatId;
+      // Prefer the more specific kind (a real kind over a null/boundary) only
+      // matters for burst continuation; keep prev.kind (earliest) as-is.
+      continue;
+    }
+    deduped.push({ ...s });
+  }
+  return deduped;
+}
+
+/**
+ * Collapse consecutive same-run agent samples into one burst segment (§5.1) so a
+ * dense burst (8 snapshots in 7 minutes) contributes its wall-clock, not a count
+ * × block. A burst is broken by any sample NOT continuing the same aiChatId
+ * agent run: a non-agent sample, a `boundary` (actor transition), or a DIFFERENT
+ * aiChatId. Only an AGENT-sourced `idle` pulse with the SAME or a null aiChatId
+ * continues the burst (its label lags the real edit ≤ maxWait, well within
+ * rounding); a user-sourced `idle` (a human supervision pulse) breaks it.
+ */
+function collapse(samples: NormSample[], config: WorkTimeConfig): Segment[] {
+  const segments: Segment[] = [];
+  let burst: { chatId: string | null; tStart: number; tEnd: number } | null =
+    null;
+
+  const flush = () => {
+    if (!burst) return;
+    let tEnd = burst.tEnd;
+    if (config.burstCapMs != null && tEnd - burst.tStart > config.burstCapMs) {
+      tEnd = burst.tStart + config.burstCapMs;
+    }
+    segments.push({ tStart: burst.tStart, tEnd, isAgent: true });
+    burst = null;
+  };
+
+  for (const s of samples) {
+    // An agent-sourced idle pulse continues the current agent burst (same or
+    // null run id). A user-sourced idle (human supervision) must NOT be swallowed
+    // here — it falls through to the human branch so the session flips to `work`.
+    if (
+      burst &&
+      s.kind === 'idle' &&
+      s.isAgent &&
+      (s.aiChatId === burst.chatId || s.aiChatId == null)
+    ) {
+      burst.tEnd = s.t;
+      continue;
+    }
+    if (s.isAgent && s.kind !== 'boundary') {
+      if (burst && burst.chatId === s.aiChatId) {
+        burst.tEnd = s.t;
+      } else {
+        flush();
+        burst = { chatId: s.aiChatId, tStart: s.t, tEnd: s.t };
+      }
+      continue;
+    }
+    // A human sample, a boundary, or an agent-boundary: breaks the burst and is
+    // itself a zero-width segment (its class follows its own source).
+    flush();
+    segments.push({ tStart: s.t, tEnd: s.t, isAgent: s.isAgent });
+  }
+  flush();
+  return segments;
+}
+
+function gapThreshold(
+  a: Segment,
+  b: Segment,
+  config: WorkTimeConfig,
+): number {
+  return a.isAgent && b.isAgent ? config.agentTGap : config.tGap;
+}
+
+/** Merge intervals; overlapping OR touching intervals are unioned. */
+function unionDuration(intervals: Array<[number, number]>): number {
+  if (intervals.length === 0) return 0;
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  let total = 0;
+  let [curStart, curEnd] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= curEnd) {
+      if (e > curEnd) curEnd = e;
+    } else {
+      total += curEnd - curStart;
+      curStart = s;
+      curEnd = e;
+    }
+  }
+  total += curEnd - curStart;
+  return total;
+}
+
+/**
+ * #395 core — estimate time worked on a page from its history timeline (§5).
+ * Pure and deterministic: no DB, no clock, no I/O.
+ *
+ * Pipeline: normalize+dedup → collapse agent bursts → ONE sessionization pass
+ * over all segments (threshold depends on the pair: both-agent → agentTGap, else
+ * tGap; the last session is ALWAYS closed after the loop) → class per finished
+ * session (all-agent → agent_only, else work) → pad each session (multi-sample
+ * → [first−P_in, last+P_out]; lone scalar → [t−P_single, t]) → clip padding of
+ * adjacent DIFFERENT-class sessions at the raw-gap midpoint (so work/agent_only
+ * never overlap) → metrics are the union wall-clock within each class (union, not
+ * Σ, so overlaps never double, and cross-class-disjoint by the clip above).
+ */
+export function computeWorkTime(
+  rows: TimelineSample[],
+  config?: Partial<WorkTimeConfig>,
+): WorkTimeResult {
+  const cfg = resolveWorkTimeConfig(config);
+  const samples = normalize(rows, cfg);
+  const segments = collapse(samples, cfg);
+
+  // Sessionize — one pass over ALL segments.
+  const rawSessions: Segment[][] = [];
+  let cur: Segment[] | null = null;
+  for (const seg of segments) {
+    if (cur == null) {
+      cur = [seg];
+    } else {
+      const last = cur[cur.length - 1];
+      if (seg.tStart - last.tEnd <= gapThreshold(last, seg, cfg)) {
+        cur.push(seg);
+      } else {
+        rawSessions.push(cur);
+        cur = [seg];
+      }
+    }
+  }
+  if (cur != null) rawSessions.push(cur); // MUST close the last session (§5, §9#1)
+
+  // A finished session with BOTH its raw (unpadded) span and its padded bounds.
+  // `rawSessions` are already in ascending time order, so `built` is too.
+  interface BuiltSession {
+    rawStart: number;
+    rawEnd: number;
+    padStart: number;
+    padEnd: number;
+    cls: WorkSession['class'];
+  }
+  const built: BuiltSession[] = [];
+
+  for (const segs of rawSessions) {
+    const first = segs[0];
+    const last = segs[segs.length - 1];
+    const cls = segs.every((s) => s.isAgent) ? 'agent_only' : 'work';
+
+    let padStart: number;
+    let padEnd: number;
+    if (segs.length === 1 && first.tStart === first.tEnd) {
+      // Lone single-instant session (one scalar, or a one-snapshot agent run):
+      // pre-roll only, no invented "future" work (§5).
+      padStart = first.tStart - cfg.pSingle;
+      padEnd = first.tStart;
+    } else {
+      padStart = first.tStart - cfg.pIn;
+      padEnd = last.tEnd + cfg.pOut;
+    }
+
+    built.push({
+      rawStart: first.tStart,
+      rawEnd: last.tEnd,
+      padStart,
+      padEnd,
+      cls,
+    });
+  }
+
+  // Clip cross-class padding so a `work` and an `agent_only` session that abut
+  // never claim the same wall-clock. For each ADJACENT pair of DIFFERENT classes,
+  // cap the earlier session's trailing pad and the later session's leading pad at
+  // the MIDPOINT of the raw (unpadded) inactivity gap between them: the earlier
+  // padded interval then ends ≤ midpoint and the later one starts ≥ midpoint, so
+  // the two are disjoint (they touch at most at the midpoint). This makes the
+  // per-class unions (workMs / agentOnlyMs) cross-class-disjoint BY CONSTRUCTION
+  // — closing the double-count where a work session ending in an agent segment
+  // and a nearby agent_only session (gap in (agentTGap, pIn+pOut]) overlapped and
+  // were counted into both metrics (§5, §9). Within-class adjacency is left
+  // untouched: `unionDuration` already dedups it, and clipping there could perturb
+  // the per-class metric value.
+  for (let i = 1; i < built.length; i++) {
+    const a = built[i - 1];
+    const b = built[i];
+    if (a.cls === b.cls) continue;
+    const midpoint = (a.rawEnd + b.rawStart) / 2;
+    if (a.padEnd > midpoint) a.padEnd = midpoint;
+    if (b.padStart < midpoint) b.padStart = midpoint;
+  }
+
+  const sessions: WorkSession[] = [];
+  const workIvs: Array<[number, number]> = [];
+  const agentIvs: Array<[number, number]> = [];
+  for (const s of built) {
+    sessions.push({ start: s.padStart, end: s.padEnd, class: s.cls });
+    (s.cls === 'work' ? workIvs : agentIvs).push([s.padStart, s.padEnd]);
+  }
+
+  sessions.sort((a, b) => a.start - b.start);
+
+  return {
+    workMs: unionDuration(workIvs),
+    agentOnlyMs: unionDuration(agentIvs),
+    sessions,
+  };
+}

apps/server/src/core/page/work-time/index.ts

@@ -0,0 +1,15 @@
+export { computeWorkTime } from './compute-work-time';
+export { bucketByDay, zonedDayStart } from './bucket-by-day';
+export {
+  DEFAULT_WORK_TIME_CONFIG,
+  resolveWorkTimeConfig,
+} from './work-time.config';
+export type { WorkTimeConfig } from './work-time.config';
+export type {
+  TimelineSample,
+  WorkSession,
+  WorkTimeResult,
+  SessionClass,
+  DayWindow,
+  PerDay,
+} from './work-time.types';

apps/server/src/core/page/work-time/work-time.config.ts

@@ -0,0 +1,102 @@
+import {
+  IDLE_MAX_WAIT_USER,
+  IDLE_MAX_WAIT_AGENT,
+} from '../../../collaboration/constants';
+
+/**
+ * #395 — tunables for the work-time estimate (§10). Defaults are calibrated off
+ * #374's idle-pulse ceilings: after #374 a continuous editing session leaves a
+ * history row at least every ~IDLE_MAX_WAIT (10m user / 5m agent), so a gap
+ * WIDER than that ceiling contains un-pulsed idle time = (partial) inactivity.
+ * `tGap` therefore sits a little above the user ceiling, `agentTGap` a little
+ * above the agent ceiling — a gap within the threshold is pulse-backed and
+ * counts as work.
+ */
+export interface WorkTimeConfig {
+  /** user inactivity timeout: gap ≤ tGap between samples = continuous work. */
+  tGap: number;
+  /** timeout for a pair of consecutive agent samples (tighter than tGap). */
+  agentTGap: number;
+  /** pre-roll padding for a multi-sample session (work began before sample 1). */
+  pIn: number;
+  /** post-roll padding for a multi-sample session (work continued after last). */
+  pOut: number;
+  /** block for a lone single-sample session (pre-roll only, no invented future). */
+  pSingle: number;
+  /** drop `git`-source samples (they are not human/agent article work). */
+  excludeGit: boolean;
+  /** optional cap on one collapsed agent-burst segment's wall-clock (§9#3). */
+  burstCapMs?: number;
+  /** samples whose createdAt round to the same bucket dedup to one (§9#7). */
+  dedupRoundMs: number;
+}
+
+export const DEFAULT_WORK_TIME_CONFIG: WorkTimeConfig = {
+  // ~15m: IDLE_MAX_WAIT_USER (10m) + headroom. Empirically backcast on a real
+  // 307-snapshot article (≈24h at 15m matched the owner's estimate; 30/45m
+  // over-counted). See #395 §10.
+  tGap: 15 * 60 * 1000,
+  // ~7m: IDLE_MAX_WAIT_AGENT (5m) + headroom.
+  agentTGap: 7 * 60 * 1000,
+  pIn: 5 * 60 * 1000,
+  pOut: 5 * 60 * 1000,
+  pSingle: 2 * 60 * 1000,
+  excludeGit: true,
+  burstCapMs: undefined,
+  dedupRoundMs: 1000,
+};
+
+// Compile-time cross-check that the defaults really are pulse-anchored — if a
+// future edit moves the #374 ceilings, this reminds us to re-calibrate.
+void IDLE_MAX_WAIT_USER;
+void IDLE_MAX_WAIT_AGENT;
+
+/**
+ * Fill a partial config with defaults and validate it. Cross-class metric
+ * disjointness is guaranteed jointly by `computeWorkTime`'s adjacent-pair padding
+ * clip (it caps the padding of adjacent DIFFERENT-class sessions at the raw-gap
+ * midpoint) AND the two bounds enforced below (§5):
+ *   - `tGap ≥ pIn + pOut`: a session's own padding never exceeds its inactivity
+ *     window.
+ *   - `2·agentTGap ≥ pIn + pOut`: makes the adjacent-only clip provably COMPLETE.
+ *     A NON-adjacent (i, i+2) cross-class overlap could only arise from two
+ *     same-class sessions separated by a full intervening session of the other
+ *     class; that separation spans at least two inter-session gaps, each strictly
+ *     `> agentTGap`, so it is `> 2·agentTGap`. Requiring `2·agentTGap ≥ pIn + pOut`
+ *     means even the widest padded reach (pIn + pOut) cannot bridge it — so the
+ *     only cross-class overlaps possible are between ADJACENT sessions, which the
+ *     clip handles. `workMs`/`agentOnlyMs` are therefore disjoint by construction.
+ */
+export function resolveWorkTimeConfig(
+  partial?: Partial<WorkTimeConfig>,
+): WorkTimeConfig {
+  const config = { ...DEFAULT_WORK_TIME_CONFIG, ...(partial ?? {}) };
+
+  for (const key of [
+    'tGap',
+    'agentTGap',
+    'pIn',
+    'pOut',
+    'pSingle',
+    'dedupRoundMs',
+  ] as const) {
+    const value = config[key];
+    if (!Number.isFinite(value) || value < 0) {
+      throw new Error(`work-time config: ${key} must be a non-negative number`);
+    }
+  }
+  if (config.burstCapMs != null && config.burstCapMs <= 0) {
+    throw new Error('work-time config: burstCapMs must be > 0 when set');
+  }
+  if (config.tGap < config.pIn + config.pOut) {
+    throw new Error(
+      "work-time config: tGap must be ≥ pIn + pOut (a session's padding may not exceed its inactivity window)",
+    );
+  }
+  if (2 * config.agentTGap < config.pIn + config.pOut) {
+    throw new Error(
+      'work-time config: 2·agentTGap must be ≥ pIn + pOut (so non-adjacent cross-class padding cannot overlap)',
+    );
+  }
+  return config;
+}

apps/server/src/core/page/work-time/work-time.types.ts

@@ -0,0 +1,73 @@
+/**
+ * #395 — "time worked on an article" domain types.
+ *
+ * The estimate is built by sessionizing a page's `page_history` timeline on
+ * inactivity gaps (WakaTime-style), NOT by taking the span between the first and
+ * last edit (which over-counts sleep / lunch / idle days). See the design doc in
+ * issue #395 §5–§6.3 for the normative algorithm.
+ */
+
+/**
+ * A single `page_history` row projected for the work-time computation — the
+ * cheap columns only (no `content`). Produced by
+ * `PageHistoryRepo.findTimelineByPageId`. `createdAt` is whatever the DB driver
+ * hands back (Date); the pure core normalizes it to epoch-ms itself so it stays
+ * deterministic and DB-free.
+ */
+export interface TimelineSample {
+  createdAt: Date | string | number;
+  lastUpdatedById: string | null;
+  /** 'user' | 'agent' | 'git' | null (legacy autosave = human). */
+  lastUpdatedSource: string | null;
+  lastUpdatedAiChatId: string | null;
+  /** #370 tier: 'manual' | 'agent' | 'idle' | 'boundary' | null (legacy). */
+  kind: string | null;
+}
+
+/** A finished session's class (§5.1). */
+export type SessionClass = 'work' | 'agent_only';
+
+/**
+ * A finished session: absolute wall-clock bounds already padded with P_in/P_out
+ * (multi-sample) or P_single (single scalar), plus its class. This is enough for
+ * both the metrics and the per-day punch-card colouring.
+ */
+export interface WorkSession {
+  /** epoch-ms, inclusive lower bound (already P-padded). */
+  start: number;
+  /** epoch-ms, exclusive upper bound (already P-padded). */
+  end: number;
+  class: SessionClass;
+}
+
+/** Output of {@link computeWorkTime}. */
+export interface WorkTimeResult {
+  /** union wall-clock of `work` sessions, ms (the headline metric). */
+  workMs: number;
+  /** union wall-clock of `agent_only` sessions, ms (secondary). */
+  agentOnlyMs: number;
+  sessions: WorkSession[];
+}
+
+/** One activity window inside a calendar day (already clipped to the day). */
+export interface DayWindow {
+  /** epoch-ms. */
+  start: number;
+  /** epoch-ms. */
+  end: number;
+  class: SessionClass;
+}
+
+/** One calendar day of the punch-card (§6.3). */
+export interface PerDay {
+  /** epoch-ms of the local-midnight day start in the requested tz. */
+  day: number;
+  /** 'YYYY-MM-DD' in the requested tz — stable, tz-independent label. */
+  dayISO: string;
+  /** Σ of `work` windows this day, ms. Σ over days == workMs (invariant §6.3). */
+  activeMs: number;
+  /** Σ of `agent_only` windows this day, ms (drawn, NOT in activeMs). */
+  agentMs: number;
+  /** both classes, clipped to the day, sorted by start (for drawing). */
+  windows: DayWindow[];
+}

apps/server/src/database/repos/page/page-history.repo.ts

@@ -157,6 +157,44 @@ export class PageHistoryRepo {
     return { ...result, items: result.items.map(attachPageHistoryAgent) };
   }
 
+  /**
+   * #395 — cheap projection of a page's FULL history timeline for the work-time
+   * estimate: only the columns the sessionizer needs, no heavy `content`, sorted
+   * oldest→newest. The secondary `id` tie-break keeps rows sharing a `createdAt`
+   * (e.g. a synchronous pre-agent boundary row + the immediate agent snapshot)
+   * in a deterministic order.
+   */
+  async findTimelineByPageId(
+    pageId: string,
+    trx?: KyselyTransaction,
+  ): Promise<
+    Array<
+      Pick<
+        PageHistory,
+        | 'createdAt'
+        | 'lastUpdatedById'
+        | 'lastUpdatedSource'
+        | 'lastUpdatedAiChatId'
+        | 'kind'
+      >
+    >
+  > {
+    const db = dbOrTx(this.db, trx);
+    return db
+      .selectFrom('pageHistory')
+      .select([
+        'createdAt',
+        'lastUpdatedById',
+        'lastUpdatedSource',
+        'lastUpdatedAiChatId',
+        'kind',
+      ])
+      .where('pageId', '=', pageId)
+      .orderBy('createdAt', 'asc')
+      .orderBy('id', 'asc')
+      .execute();
+  }
+
   async findPageLastHistory(
     pageId: string,
     opts?: {

apps/server/src/integrations/static/static.module.ts

@@ -4,7 +4,6 @@ import { join } from 'path';
 import * as fs from 'node:fs';
 import fastifyStatic from '@fastify/static';
 import { EnvironmentService } from '../environment/environment.service';
-import { resolveClientDistPath } from '../../common/helpers/client-version';
 
 /**
  * Resolve the response headers for a statically served client asset.
@@ -57,7 +56,14 @@ export class StaticModule implements OnModuleInit {
     const httpAdapter = this.httpAdapterHost.httpAdapter;
     const app = httpAdapter.getInstance();
 
-    const clientDistPath = resolveClientDistPath();
+    const clientDistPath = join(
+      __dirname,
+      '..',
+      '..',
+      '..',
+      '..',
+      'client/dist',
+    );
 
     const indexFilePath = join(clientDistPath, 'index.html');
 

apps/server/src/ws/ws.gateway.ts

@@ -9,14 +9,10 @@ import {
 import { Server, Socket } from 'socket.io';
 import { TokenService } from '../core/auth/services/token.service';
 import { JwtPayload, JwtType } from '../core/auth/dto/jwt-payload';
-import { Logger, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
+import { OnModuleDestroy } from '@nestjs/common';
 import { SpaceMemberRepo } from '@docmost/db/repos/space/space-member.repo';
 import { WsService } from './ws.service';
 import { getSpaceRoomName, getUserRoomName } from './ws.utils';
-import {
-  readClientBuildVersion,
-  resolveClientDistPath,
-} from '../common/helpers/client-version';
 import * as cookie from 'cookie';
 
 @WebSocketGateway({
@@ -24,40 +20,17 @@ import * as cookie from 'cookie';
   transports: ['websocket'],
 })
 export class WsGateway
-  implements
-    OnGatewayConnection,
-    OnGatewayInit,
-    OnModuleInit,
-    OnModuleDestroy
+  implements OnGatewayConnection, OnGatewayInit, OnModuleDestroy
 {
   @WebSocketServer()
   server: Server;
 
-  private readonly logger = new Logger(WsGateway.name);
-
-  // The build version of the client bundle shipped in this image, read once at
-  // startup from client/dist/version.json (single source of truth, same value
-  // baked into the client's APP_VERSION). Empty string => version.json missing
-  // or empty => the proactive version-coherence reload feature stays inert.
-  private appVersion = '';
-
   constructor(
     private tokenService: TokenService,
     private spaceMemberRepo: SpaceMemberRepo,
     private wsService: WsService,
   ) {}
 
-  onModuleInit(): void {
-    this.appVersion = readClientBuildVersion(resolveClientDistPath());
-    if (this.appVersion) {
-      this.logger.log(`app-version reload: ACTIVE (v=${this.appVersion})`);
-    } else {
-      this.logger.log(
-        'app-version reload: DISABLED (version.json missing/empty)',
-      );
-    }
-  }
-
   afterInit(server: Server): void {
     this.wsService.setServer(server);
   }
@@ -82,14 +55,6 @@ export class WsGateway
       const spaceRooms = userSpaceIds.map((id) => getSpaceRoomName(id));
 
       client.join([userRoom, workspaceRoom, ...spaceRooms]);
-
-      // Announce this container's client build version to the freshly
-      // authenticated socket. On a redeploy the client reconnects to the new
-      // container and receives the new version here, letting it guard-reload
-      // before it hits a stale lazy chunk. Per-connect only (no broadcast):
-      // natural reconnect covers both single-container and cluster without a
-      // thundering-herd fleet reload.
-      client.emit('app-version', { version: this.appVersion });
     } catch (err) {
       client.emit('Unauthorized');
       client.disconnect();

apps/server/test/integration/page-work-time.int-spec.ts

@@ -0,0 +1,137 @@
+import { randomUUID } from 'node:crypto';
+import { Kysely } from 'kysely';
+import { PageHistoryRepo } from '../../src/database/repos/page/page-history.repo';
+import { PageHistoryService } from '../../src/core/page/services/page-history.service';
+import { computeWorkTime } from '../../src/core/page/work-time';
+import {
+  getTestDb,
+  destroyTestDb,
+  createWorkspace,
+  createSpace,
+  createPage,
+  createUser,
+  createChat,
+} from './db';
+
+/**
+ * #395 — real-Postgres coverage for the work-time timeline projection and the
+ * service that computes the estimate. The pure sessionizer is unit-tested
+ * exhaustively (compute-work-time.spec.ts); this asserts the SQL projection
+ * (right rows, ASC, no `content`) and that the service's numbers agree with the
+ * pure core over the exact rows the DB returns.
+ */
+describe('PageHistory work-time [integration]', () => {
+  let db: Kysely<any>;
+  let repo: PageHistoryRepo;
+  let service: PageHistoryService;
+  let workspaceId: string;
+  let spaceId: string;
+  let pageId: string;
+  let userId: string;
+  let chatId: string;
+
+  const MIN = 60 * 1000;
+
+  beforeAll(async () => {
+    db = getTestDb();
+    repo = new PageHistoryRepo(db as any);
+    service = new PageHistoryService(repo);
+    workspaceId = (await createWorkspace(db)).id;
+    spaceId = (await createSpace(db, workspaceId)).id;
+    pageId = (await createPage(db, { workspaceId, spaceId })).id;
+    userId = (await createUser(db, workspaceId)).id;
+    chatId = (await createChat(db, { workspaceId, creatorId: userId })).id;
+  });
+
+  afterAll(async () => {
+    await destroyTestDb();
+  });
+
+  async function insertHistory(rows: Array<{
+    createdAt: string;
+    source: string | null;
+    chat?: string | null;
+    kind?: string | null;
+    content?: unknown;
+  }>) {
+    for (const r of rows) {
+      await db
+        .insertInto('pageHistory')
+        .values({
+          id: randomUUID(),
+          pageId,
+          spaceId,
+          workspaceId,
+          title: 'x',
+          content: r.content ?? { type: 'doc', content: [] },
+          lastUpdatedById: userId,
+          lastUpdatedSource: r.source,
+          lastUpdatedAiChatId: r.chat ?? null,
+          kind: r.kind ?? null,
+          createdAt: new Date(r.createdAt),
+        })
+        .execute();
+    }
+  }
+
+  it('findTimelineByPageId projects the cheap columns, ASC, without content', async () => {
+    await insertHistory([
+      { createdAt: '2026-07-04T19:54:00Z', source: 'user', kind: 'manual' },
+      { createdAt: '2026-07-04T03:40:00Z', source: 'user', kind: null },
+      { createdAt: '2026-07-04T15:43:00Z', source: 'agent', chat: chatId, kind: 'agent' },
+    ]);
+
+    const timeline = await repo.findTimelineByPageId(pageId);
+    expect(timeline).toHaveLength(3);
+    // Sorted oldest → newest.
+    const times = timeline.map((r) => new Date(r.createdAt).getTime());
+    expect(times).toEqual([...times].sort((a, b) => a - b));
+    // Projection carries exactly the sessionizer's inputs, and NO content.
+    for (const row of timeline) {
+      expect(row).toHaveProperty('createdAt');
+      expect(row).toHaveProperty('lastUpdatedById');
+      expect(row).toHaveProperty('lastUpdatedSource');
+      expect(row).toHaveProperty('lastUpdatedAiChatId');
+      expect(row).toHaveProperty('kind');
+      expect(row).not.toHaveProperty('content');
+    }
+    // Agent row keeps its provenance.
+    const agent = timeline.find((r) => r.lastUpdatedSource === 'agent');
+    expect(agent?.lastUpdatedAiChatId).toBe(chatId);
+  });
+
+  it('service estimate matches the pure core and satisfies Σ perDay == workMs', async () => {
+    const rows = await repo.findTimelineByPageId(pageId);
+    const pure = computeWorkTime(rows);
+
+    const result = await service.computeWorkTime(pageId, 'UTC');
+    expect(result.workMs).toBe(pure.workMs);
+    expect(result.agentOnlyMs).toBe(pure.agentOnlyMs);
+    expect(result.tz).toBe('UTC');
+    expect(result.config.tGap).toBe(15 * MIN);
+
+    const sumActive = result.perDay.reduce((a, d) => a + d.activeMs, 0);
+    expect(sumActive).toBe(result.workMs);
+
+    // The 3 seeded rows sessionize into ≤ their span; not the naive span.
+    const naive =
+      new Date('2026-07-04T19:54:00Z').getTime() -
+      new Date('2026-07-04T03:40:00Z').getTime();
+    expect(result.workMs).toBeGreaterThan(0);
+    expect(result.workMs).toBeLessThan(naive);
+  });
+
+  it('an unknown timezone surfaces as a RangeError (controller maps to 400)', async () => {
+    await expect(
+      service.computeWorkTime(pageId, 'Not/AZone'),
+    ).rejects.toBeInstanceOf(RangeError);
+  });
+
+  it('a page with no history → zeros, no days', async () => {
+    const emptyPage = (await createPage(db, { workspaceId, spaceId })).id;
+    const result = await service.computeWorkTime(emptyPage, 'UTC');
+    expect(result.workMs).toBe(0);
+    expect(result.agentOnlyMs).toBe(0);
+    expect(result.perDay).toEqual([]);
+  });
+});