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>

services/api/internal/auth/pgstore.go

@@ -370,6 +370,22 @@ func (s *PgStore) DeleteUser(ctx context.Context, id uuid.UUID) error {
 	return nil
 }
 
+// ResetRecommendations реализует Store. Сессии волны остаются — играющая волна не ломается;
+// без показов бандит при ночном пересчёте начинает заново.
+func (s *PgStore) ResetRecommendations(ctx context.Context, id uuid.UUID) error {
+	for _, q := range []string{
+		`DELETE FROM user_profiles_rec WHERE user_id = $1`,
+		`DELETE FROM user_track_stats WHERE user_id = $1`,
+		`DELETE FROM wave_impressions WHERE wave_session_id IN (SELECT id FROM wave_sessions WHERE user_id = $1)`,
+		`DELETE FROM rec_impression_features WHERE wave_session_id IN (SELECT id FROM wave_sessions WHERE user_id = $1)`,
+	} {
+		if _, err := s.q.Exec(ctx, q, id); err != nil {
+			return fmt.Errorf("auth: reset recommendations: %w", err)
+		}
+	}
+	return nil
+}
+
 // ListAudit реализует Store.
 func (s *PgStore) ListAudit(ctx context.Context, before uuid.UUID, limit int) ([]AuditRecord, error) {
 	rows, err := s.q.Query(ctx, `