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/authtest/memstore.go

@@ -25,6 +25,8 @@ type MemStore struct {
 	Audit    []auth.AuditEntry
 	AuditIDs []uuid.UUID
 	Settings map[string]any
+	// RecResets — для кого сбрасывали рекомендации (таблиц рекомендатора в памяти нет).
+	RecResets []uuid.UUID
 }
 
 // NewMemStore создаёт пустое хранилище.
@@ -50,15 +52,16 @@ func (s *MemStore) WithTx(_ context.Context, fn func(auth.Store) error) error {
 	unlock := s.lock()
 	defer unlock()
 	users, tokens, settings := maps.Clone(s.Users), maps.Clone(s.Tokens), maps.Clone(s.Settings)
-	audit, auditIDs := slices.Clone(s.Audit), slices.Clone(s.AuditIDs)
+	audit, auditIDs, resets := slices.Clone(s.Audit), slices.Clone(s.AuditIDs), slices.Clone(s.RecResets)
 	tx := &MemStore{
 		mu: s.mu, inTx: true, Users: s.Users, Tokens: s.Tokens, Audit: s.Audit, AuditIDs: s.AuditIDs, Settings: s.Settings,
+		RecResets: s.RecResets,
 	}
 	if err := fn(tx); err != nil {
-		s.Users, s.Tokens, s.Audit, s.AuditIDs, s.Settings = users, tokens, audit, auditIDs, settings
+		s.Users, s.Tokens, s.Audit, s.AuditIDs, s.Settings, s.RecResets = users, tokens, audit, auditIDs, settings, resets
 		return err
 	}
-	s.Users, s.Tokens, s.Audit, s.AuditIDs, s.Settings = tx.Users, tx.Tokens, tx.Audit, tx.AuditIDs, tx.Settings
+	s.Users, s.Tokens, s.Audit, s.AuditIDs, s.Settings, s.RecResets = tx.Users, tx.Tokens, tx.Audit, tx.AuditIDs, tx.Settings, tx.RecResets
 	return nil
 }
 
@@ -319,6 +322,13 @@ func (s *MemStore) ResetPassword(_ context.Context, id uuid.UUID, hash string) e
 	})
 }
 
+// ResetRecommendations реализует auth.Store.
+func (s *MemStore) ResetRecommendations(_ context.Context, id uuid.UUID) error {
+	defer s.lock()()
+	s.RecResets = append(s.RecResets, id)
+	return nil
+}
+
 // DeleteUser реализует auth.Store: токены удаляются, ссылки в журнале обнуляются, как в PostgreSQL.
 func (s *MemStore) DeleteUser(_ context.Context, id uuid.UUID) error {
 	defer s.lock()()