feat: Move notification settings to user profile and add i18n support

- Move notification config from system settings (.env) to user profile (database)
- Add user-specific notification settings API endpoints (GET/PUT /api/user/notification-settings)
- Add notification_settings column to qd_users table
- Update portfolio and trading-assistant to use profile notification settings
- Add notification settings UI in profile page with all channels (browser, telegram, email, phone, discord, webhook)
- Add i18n translations for notification settings in 10 languages
- Fix timestamp parsing in TradingRecords and portfolio (handle both ISO strings and Unix timestamps)
- Fix header icons alignment for mobile responsive layout
- Fix equity curve timestamp bug (handle datetime objects properly)
- Remove unused login.js exports and clean up user.js store
- Remove husky, commitlint and other dev dependencies
- Clean up env.example by removing user-specific notification params
- Update signal_notifier to prioritize user-specific tokens over global env vars

backend_api_python/app/routes/strategy.py

@@ -471,7 +471,13 @@ def get_equity_curve():
                 equity += float(r.get('profit') or 0)
             except Exception:
                 pass
-            ts = int(r.get('created_at').timestamp() or time.time())
+            created_at = r.get('created_at')
+            if created_at and hasattr(created_at, 'timestamp'):
+                ts = int(created_at.timestamp())
+            elif created_at:
+                ts = int(created_at)
+            else:
+                ts = int(time.time())
             curve.append({'time': ts, 'equity': equity})
 
         return jsonify({'code': 1, 'msg': 'success', 'data': curve})