2026-08-27 调试完成版本

- FC 控制指令域修正：payload 14→18 字节，纵倾/横倾姿态拆分为数据1/数据2
- WebServer 广播改为待发队列模式，修复 mongoose 跨线程调用问题
- build-board.sh 增加板卡组网说明(/23 掩码方案)、pCCU 服务部署与 mission 同步
- 同步 0824 协议文档更新

src/pCCU/CCU.cpp

@@ -218,13 +218,15 @@ void CCU::handlePmMessage(Message* msg, const std::vector<uint8_t>& frame) {
                 LOG_F(INFO, "[PM] control: mode=%d cmd=%d power=%d",
                       c.mode, c.cmd, c.outputPower);
 
-                // 映射并转发到 FC
+                // 映射并转发到 FC（1.1.1：姿态为双通道 int16，PM 单通道填数据1）
                 FcControlValue f;
                 f.mode           = c.mode;
                 f.cmd            = c.cmd;
                 f.outputPower    = c.outputPower;
-                f.pitch          = c.pitch;
-                f.roll           = c.roll;
+                f.pitch1         = c.pitch;
+                f.pitch2         = 0;
+                f.roll1          = c.roll;
+                f.roll2          = 0;
                 f.emergencyAllow = c.emergencyAllow;
                 f.depth          = c.depth;
                 f.supplyCmd      = c.supplyCmd;