feat(push): add JPush integration for offline message push

Add JPush (极光推送) integration to enable push notifications for offline users. This includes:
- New jpush client package with API for batch push notifications
- Configuration for jpush (enabled, app_key, master_secret, production mode)
- Updated push service to send messages via JPush when users are offline
- Added PushChatMessage method with do-not-disturb checking
- Integrated push service with chat service to notify offline users of new messages
- Updated deployment workflow with JPush and related environment variables

internal/repository/device_token_repo.go

@@ -124,9 +124,11 @@ func (r *deviceTokenRepository) Upsert(token *model.DeviceToken) error {
 		return err
 	}
 
-	// 更新现有记录
+	// 更新现有记录（包括 user_id，设备可能在用户间转移）
 	return r.db.Model(&existing).Updates(map[string]any{
+		"user_id":      token.UserID,
 		"push_token":   token.PushToken,
+		"device_type":  token.DeviceType,
 		"is_active":    true,
 		"device_name":  token.DeviceName,
 		"last_used_at": time.Now(),