fix(privacy): "Remove Photo Metadata" also covers emoji/sticker packs and badges (#332)

Custom emoji and sticker images, pack avatars and power-level badge
images were uploaded with their EXIF intact (GPS location, timestamp),
although they are published to every member of the room or space. Route
those three pickers through a new useStrippedFilePicker, which applies
the same stripImageMetadata as attachments and avatars.

Fixes #332

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/hooks/useStrippedFilePicker.ts

@@ -0,0 +1,36 @@
+import { useCallback } from 'react';
+import { useFilePicker } from './useFilePicker';
+import { useSetting } from '../state/hooks/settings';
+import { settingsAtom } from '../state/settings';
+import { stripImageMetadata } from '../utils/stripImageMetadata';
+
+/**
+ * [Gitea #332] `useFilePicker` for images that get published (emoji / sticker
+ * packs, pack avatars, power-level badges): applies "Remove Photo Metadata"
+ * like message attachments and avatars, so a phone photo's GPS location and
+ * timestamp don't go to every member of the room or space.
+ */
+export const useStrippedFilePicker = <M extends boolean | undefined = undefined>(
+  onSelect: (file: M extends true ? File[] : File) => void,
+  multiple?: M,
+) => {
+  const [strip] = useSetting(settingsAtom, 'stripImageMetadata');
+  const handle = useCallback(
+    (picked: File | File[]) => {
+      if (!strip) {
+        onSelect(picked as M extends true ? File[] : File);
+        return;
+      }
+      const clean = (f: File) => stripImageMetadata(f).then((r) => r.file);
+      if (Array.isArray(picked)) {
+        Promise.all(picked.map(clean)).then((files) =>
+          onSelect(files as M extends true ? File[] : File),
+        );
+      } else {
+        clean(picked).then((file) => onSelect(file as M extends true ? File[] : File));
+      }
+    },
+    [strip, onSelect],
+  );
+  return useFilePicker(handle as (file: M extends true ? File[] : File) => void, multiple);
+};