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/core/SnapshotBuilder.cpp

@@ -172,8 +172,10 @@ JsonVal fcControlJson(const FcControlValue& v) {
     put(j, "mode", v.mode);
     put(j, "cmd", v.cmd);
     put(j, "outputPower", v.outputPower);
-    j["pitch"] = JsonVal(static_cast<int>(v.pitch)); // 有符号 int16，×0.1°
-    j["roll"]  = JsonVal(static_cast<int>(v.roll));
+    j["pitch1"] = JsonVal(static_cast<int>(v.pitch1)); // 有符号 int16，×0.1°
+    j["pitch2"] = JsonVal(static_cast<int>(v.pitch2));
+    j["roll1"]  = JsonVal(static_cast<int>(v.roll1));
+    j["roll2"]  = JsonVal(static_cast<int>(v.roll2));
     put(j, "emergencyAllow", v.emergencyAllow);
     put(j, "depth", v.depth);
     put(j, "supplyCmd", v.supplyCmd);