调通串口与上位机双向通信

- UART2 TX: 硬件FIFO+DMA+块传输模式，非阻塞发送
- UART2 RX: 硬件FIFO+中断+软件FIFO，状态机解析协议帧
- 协议: [SOF:0xA7][cmd:1][checksum:1]，支持自动/手动/调试模式切换
- 更新.gitignore忽略*.log文件

.gitignore

@@ -1,10 +1,11 @@
-/libraries/sdk/ti_config/excluded
-
-/project/keil/Listings/
-/project/keil/Objects/
-
-uv4.log
-uv4.log.lock
-keil-assistant.log
-
+/libraries/sdk/ti_config/excluded
+
+/project/keil/Listings/
+/project/keil/Objects/
+
+uv4.log
+uv4.log.lock
+keil-assistant.log
+*.log
+
 CLAUDE.md