feat(admin): reset a user's recommendations from the users panel

- POST /admin/users/{id}/reset-recommendations clears the taste profile
  (onboarding, CF vector, bandit), play stats and wave impressions; likes,
  dislikes and history stay, wave sessions stay so a playing wave keeps going
- moderators may reset plain users, admins anyone including themselves;
  the reset is written to the audit log
- users panel gets the menu action with a confirmation; docs updated

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/test/fakeApi.ts

@@ -223,6 +223,8 @@ export function fakeApi(initial: FakeUser[]) {
       case `GET /api/v1/artists/${kino.id}/albums`:
         return json({ items: [albumSummary] });
     }
+    if (req.method === 'POST' && /^\/api\/v1\/admin\/users\/[^/]+\/reset-recommendations$/.test(path))
+      return new Response(null, { status: 204 });
     const reactionPath = /^\/api\/v1\/me\/reactions\/tracks\/([^/]+)$/.exec(path);
     if (reactionPath) {
       if (req.method === 'PUT') reactions.set(reactionPath[1]!, body?.reaction as 'like' | 'dislike');