Feature/custom strategy (#1172)

* feat: add Strategy Studio with multi-timeframe support
- Add Strategy Studio page with three-column layout for strategy management
- Support multi-timeframe K-line data selection (5m, 15m, 1h, 4h, etc.)
- Add GetWithTimeframes() function in market package for fetching multiple timeframes
- Add TimeframeSeriesData struct for storing per-timeframe technical indicators
- Update formatMarketData() to display all selected timeframes in AI prompt
- Add strategy API endpoints for CRUD operations and test run
- Integrate real AI test runs with configured AI models
- Support custom AI500 and OI Top API URLs from strategy config
* docs: add Strategy Studio screenshot to README files
* fix: correct strategy-studio.png filename case in README
* refactor: remove legacy signal source config and simplify trader creation
- Remove signal source configuration from traders page (now handled by strategy)
- Remove advanced options (legacy config) from TraderConfigModal
- Rename default strategy to "默认山寨策略" with AI500 coin pool URL
- Delete SignalSourceModal and SignalSourceWarning components
- Clean up related stores, hooks, and page components

store/exchange.go

@@ -56,8 +56,7 @@ func (s *ExchangeStore) initTables() error {
 			lighter_api_key_private_key TEXT DEFAULT '',
 			created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
 			updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-			PRIMARY KEY (id, user_id),
-			FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+			PRIMARY KEY (id, user_id)
 		)
 	`)
 	if err != nil {