fix(work-time): user idle breaks agent burst; cap tz length (#395)

Only an agent-sourced idle pulse extends an agent burst; a user idle
(human supervision) now falls through to the human branch so the session
is classified `work`, not `agent_only`. Add @MaxLength(64) to tz to match
its comment.

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

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';
 
@@ -54,6 +55,7 @@ export class PageWorkTimeDto extends PageIdDto {
   // throws on an unknown zone (caught by the controller → 400).
   @IsOptional()
   @IsString()
+  @MaxLength(64)
   tz?: string;
 }
 

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

@@ -159,6 +159,29 @@ describe('computeWorkTime', () => {
     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'),

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

@@ -81,8 +81,9 @@ function normalize(
  * 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. An `idle` pulse with the SAME or a null aiChatId continues the burst
- * (its label lags the real edit ≤ maxWait, well within rounding).
+ * 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[] = [];
@@ -100,8 +101,15 @@ function collapse(samples: NormSample[], config: WorkTimeConfig): Segment[] {
   };
 
   for (const s of samples) {
-    // idle pulse continuing the current agent burst (same or null run id).
-    if (burst && s.kind === 'idle' && (s.aiChatId === burst.chatId || s.aiChatId == null)) {
+    // 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;
     }