Safety screens: followers, blocking, reporting, admin

Web and mobile:
- Follower/following lists (tap the counts), with Follow buttons and
  "Remove" on your own followers.
- Profile ⋯ menu: block (with confirmation) / unblock, and report with a
  reason and optional note. "Follows you" label, "Follow back", and a
  banner on profiles you've blocked.
- Blocked accounts list in Settings, with unblock.
Web only: /admin for the admin account: stats, open/resolved reports,
resolve, suspend/unsuspend.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

apps/mobile/src/app/u/[username]/followers.tsx

@@ -0,0 +1,12 @@
+import { Stack, useLocalSearchParams } from 'expo-router';
+import { FollowList } from '@/components/FollowList';
+
+export default function FollowersScreen() {
+  const { username } = useLocalSearchParams<{ username: string }>();
+  return (
+    <>
+      <Stack.Screen options={{ title: 'Followers' }} />
+      <FollowList username={username} direction="followers" />
+    </>
+  );
+}