feat: refactor trade API to return execution status with signature

- Bump version from 1.2.0 to 1.2.1
- Change trade methods return type from Signature to (bool, Signature)
- Improve parallel execution error handling and status tracking
- Update CLI examples to match new API interface
- Enhance transaction success/failure reporting capabilities

Breaking Change: Trade API now returns tuple (success_status, signature)

src/trading/core/executor.rs

@@ -26,7 +26,7 @@ impl GenericTradeExecutor {
 
 #[async_trait::async_trait]
 impl TradeExecutor for GenericTradeExecutor {
-    async fn swap(&self, params: SwapParams) -> Result<Signature> {
+    async fn swap(&self, params: SwapParams) -> Result<(bool, Signature)> {
         let start = Instant::now();
         // 暂时支持这三种。后续重构扩展builder 支持所有的 swap
         let is_buy = params.input_mint == crate::constants::SOL_TOKEN_ACCOUNT