fix(page-templates): show a template marker icon in the page tree (#38)

Template pages were toggleable but indistinguishable in the sidebar tree.
Render an IconTemplate next to the title when node.isTemplate is true, wrapped
in a Tooltip(label='Template') with an aria-label + role='img' for AT. The
icon is a child of the row Link so clicks navigate as normal; pointer events
stay enabled so the tooltip's hover handlers fire. Adds the 'Template' i18n
key to en-US and ru-RU (other locales fall back to en-US).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -183,6 +183,7 @@
   "Successfully imported": "Successfully imported",
   "Successfully restored": "Successfully restored",
   "System settings": "System settings",
+  "Template": "Template",
   "Templates": "Templates",
   "Theme": "Theme",
   "To change your email, you have to enter your password and new email.": "To change your email, you have to enter your password and new email.",

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

@@ -183,6 +183,7 @@
   "Successfully imported": "Успешно импортировано",
   "Successfully restored": "Успешно восстановлено",
   "System settings": "Системные настройки",
+  "Template": "Шаблон",
   "Templates": "Шаблоны",
   "Theme": "Тема",
   "To change your email, you have to enter your password and new email.": "Чтобы изменить электронную почту, вам нужно ввести пароль и новый адрес.",

apps/client/src/features/page/tree/components/space-tree-row.tsx

@@ -2,13 +2,14 @@ import { useRef } from "react";
 import { Link, useParams } from "react-router-dom";
 import { useAtom } from "jotai";
 import { useTranslation } from "react-i18next";
-import { ActionIcon, rem } from "@mantine/core";
+import { ActionIcon, rem, Tooltip } from "@mantine/core";
 import {
   IconChevronDown,
   IconChevronRight,
   IconFileDescription,
   IconPlus,
   IconPointFilled,
+  IconTemplate,
 } from "@tabler/icons-react";
 
 import EmojiPicker from "@/components/ui/emoji-picker.tsx";
@@ -171,6 +172,25 @@ export function SpaceTreeRow({
 
       <span className={classes.text}>{node.name || t("untitled")}</span>
 
+      {node.isTemplate === true && (
+        <Tooltip label={t("Template")} withArrow>
+          <IconTemplate
+            size={14}
+            stroke={1.5}
+            // Visual-only indicator: subtle and never shrinks. Pointer events
+            // stay enabled so the Tooltip's hover handlers fire; clicks fall
+            // through to the row link since no stopPropagation is used.
+            style={{
+              flexShrink: 0,
+              marginLeft: rem(4),
+              color: "var(--mantine-color-dimmed)",
+            }}
+            aria-label={t("Template")}
+            role="img"
+          />
+        </Tooltip>
+      )}
+
       <div className={classes.actions}>
         <NodeMenu node={node} canEdit={canEdit} />