feat: forgot account reset flow + frontend default model fix to GLM

- Add forgot account reset flow with wallet preservation
- Update frontend default model references from DeepSeek to GLM
- Add reset-account API endpoint
- Add orphan record adoption for wallet/exchange preservation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

store/ai_model.go

@@ -54,6 +54,24 @@ func (s *AIModelStore) initDefaultData() error {
 	return nil
 }
 
+// FindOrphanClaw402 finds a claw402 model whose user_id no longer exists in the users table.
+// Used to recover wallets after account reset.
+func (s *AIModelStore) FindOrphanClaw402() (*AIModel, error) {
+	var model AIModel
+	err := s.db.Where("provider = ? AND api_key != '' AND user_id NOT IN (SELECT id FROM users)", "claw402").
+		First(&model).Error
+	if err != nil {
+		return nil, err
+	}
+	return &model, nil
+}
+
+// AdoptModel re-assigns an existing model to a new user.
+func (s *AIModelStore) AdoptModel(modelID, newUserID string) error {
+	return s.db.Model(&AIModel{}).Where("id = ?", modelID).
+		Update("user_id", newUserID).Error
+}
+
 // List retrieves user's AI model list
 func (s *AIModelStore) List(userID string) ([]*AIModel, error) {
 	var models []*AIModel

store/user.go

@@ -112,6 +112,11 @@ func (s *UserStore) UpdatePassword(userID, passwordHash string) error {
 	}).Error
 }
 
+// DeleteAll deletes all users (reset system to uninitialized state)
+func (s *UserStore) DeleteAll() error {
+	return s.db.Session(&gorm.Session{AllowGlobalUpdate: true}).Delete(&User{}).Error
+}
+
 // EnsureAdmin ensures admin user exists
 func (s *UserStore) EnsureAdmin() error {
 	var count int64