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/position.go

@@ -69,7 +69,11 @@ func (s *PositionStore) InitTables() error {
 		return fmt.Errorf("创建trader_positions表失败: %w", err)
 	}
 
-	// 创建索引
+	// 迁移：为现有表添加 exchange_id 列（如果不存在）
+	// 必须在创建索引之前执行！
+	s.db.Exec(`ALTER TABLE trader_positions ADD COLUMN exchange_id TEXT NOT NULL DEFAULT ''`)
+
+	// 创建索引（在迁移之后）
 	indices := []string{
 		`CREATE INDEX IF NOT EXISTS idx_positions_trader ON trader_positions(trader_id)`,
 		`CREATE INDEX IF NOT EXISTS idx_positions_exchange ON trader_positions(exchange_id)`,
@@ -84,9 +88,6 @@ func (s *PositionStore) InitTables() error {
 		}
 	}
 
-	// 迁移：为现有表添加 exchange_id 列（如果不存在）
-	s.db.Exec(`ALTER TABLE trader_positions ADD COLUMN exchange_id TEXT NOT NULL DEFAULT ''`)
-
 	return nil
 }