diff --git a/src/apps/officer-web/lib/i18n.ts b/src/apps/officer-web/lib/i18n.ts
index 1de5c1fd..f32877ad 100644
--- a/src/apps/officer-web/lib/i18n.ts
+++ b/src/apps/officer-web/lib/i18n.ts
@@ -1,14 +1,32 @@
 import type { TranslationKeys } from 'i18n';
 import type { InterpolationParams } from 'i18n';
+import { useCallback } from 'react';
 import { useTranslation as useTranslationBase } from 'i18n';
 import type en from '../locales/en-GB.json';
+import type uiEn from '@/components/locales/en-GB.json';
 
 type AppTranslationKey = TranslationKeys<typeof en>;
+type UiTranslationKey = TranslationKeys<typeof uiEn>;
 
-// The `app.` prefix is namespace wiring for the merged catalog (D6) — callers never spell it, they
-// pass the same bare key the JSON file uses.
+/**
+ * `t` for this workspace's own catalog, `tUi` for the shared-component one.
+ *
+ * Both are here rather than in two imports because "Cancel", "Close" and "Search" recur across the
+ * shell and genuinely belong to `ui.*` — phase 1 put them there so phases 2 and 3 could reach for them
+ * instead of inventing a second key for the same word. Anything feature-specific stays in `app.*`:
+ * per D6 a `ui.*` key may not name a feature.
+ *
+ * Both are memoized. An unstable `t` is unusable in a dependency array, and this repo has already lost
+ * days to exactly that shape — see platform/CLAUDE.md on `useClient()` and the Jellyfin player.
+ */
 export const useTranslation = () => {
   const { t: baseT, locale } = useTranslationBase();
-  const t = (key: AppTranslationKey, params?: InterpolationParams) => baseT(`app.${key}`, params);
-  return { t, locale };
+
+  const t = useCallback((key: AppTranslationKey, params?: InterpolationParams) => baseT(`app.${key}`, params), [baseT]);
+
+  const tUi = useCallback((key: UiTranslationKey, params?: InterpolationParams) => baseT(`ui.${key}`, params), [baseT]);
+
+  return { t, tUi, locale };
 };
+
+export type { AppTranslationKey };
diff --git a/src/workspaces/components/locales/useTranslation.ts b/src/workspaces/components/locales/useTranslation.ts
index eca7dd5c..9c49a13c 100644
--- a/src/workspaces/components/locales/useTranslation.ts
+++ b/src/workspaces/components/locales/useTranslation.ts
@@ -1,4 +1,5 @@
 import type { InterpolationParams, TranslationKeys } from 'i18n';
+import { useCallback } from 'react';
 import { useTranslation as useTranslationBase } from 'i18n';
 import type en from './en-GB.json';
 
@@ -8,6 +9,8 @@ type UiTranslationKey = TranslationKeys<typeof en>;
 // pass the same bare key the JSON file uses. `ui.*` may not name a feature (see the naming convention).
 export const useTranslation = () => {
   const { t: baseT, locale } = useTranslationBase();
-  const t = (key: UiTranslationKey, params?: InterpolationParams) => baseT(`ui.${key}`, params);
+  // Memoized: an unstable `t` is unusable in a dependency array. See platform/CLAUDE.md on the
+  // `useClient()` trap that silently disabled the Jellyfin player's playback reports.
+  const t = useCallback((key: UiTranslationKey, params?: InterpolationParams) => baseT(`ui.${key}`, params), [baseT]);
   return { t, locale };
 };
diff --git a/src/workspaces/officerdev/src/locales/useTranslation.ts b/src/workspaces/officerdev/src/locales/useTranslation.ts
index 1f1dd07b..cd16ad69 100644
--- a/src/workspaces/officerdev/src/locales/useTranslation.ts
+++ b/src/workspaces/officerdev/src/locales/useTranslation.ts
@@ -1,4 +1,5 @@
 import type { InterpolationParams, TranslationKeys } from 'i18n';
+import { useCallback } from 'react';
 import { useTranslation as useTranslationBase } from 'i18n';
 import type en from './en-GB.json';
 
@@ -8,6 +9,11 @@ type PanelTranslationKey = TranslationKeys<typeof en>;
 // pass the same bare key the JSON file uses.
 export const useTranslation = () => {
   const { t: baseT, locale } = useTranslationBase();
-  const t = (key: PanelTranslationKey, params?: InterpolationParams) => baseT(`panel.${key}`, params);
+  // Memoized: an unstable `t` is unusable in a dependency array. See platform/CLAUDE.md on the
+  // `useClient()` trap that silently disabled the Jellyfin player's playback reports.
+  const t = useCallback(
+    (key: PanelTranslationKey, params?: InterpolationParams) => baseT(`panel.${key}`, params),
+    [baseT],
+  );
   return { t, locale };
 };