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/web/WebServer.cpp

@@ -43,16 +43,14 @@ void WebServer::handleEvent(struct mg_connection* c, int ev, void* ev_data) {
 
         mg_http_reply(c, 404, "Content-Type: text/plain\r\n", "Not Found\n");
     } else if (ev == MG_EV_WS_OPEN) {
-        std::lock_guard<std::mutex> lock(m_wsMutex);
+        // Web 线程内：先构建欢迎快照（可能涉及 DB 查询，勿持锁），再登记连接
+        std::string welcome;
+        if (m_onOpen) welcome = m_onOpen();
         m_wsConnections.push_back(c);
-        if (m_onOpen) {
-            std::string welcome = m_onOpen();
-            if (!welcome.empty()) {
-                mg_ws_send(c, welcome.c_str(), welcome.size(), WEBSOCKET_OP_TEXT);
-            }
+        if (!welcome.empty()) {
+            mg_ws_send(c, welcome.c_str(), welcome.size(), WEBSOCKET_OP_TEXT);
         }
     } else if (ev == MG_EV_CLOSE || ev == MG_EV_ERROR) {
-        std::lock_guard<std::mutex> lock(m_wsMutex);
         for (auto it = m_wsConnections.begin(); it != m_wsConnections.end(); ++it) {
             if (*it == c) {
                 m_wsConnections.erase(it);
@@ -103,7 +101,7 @@ void WebServer::stop() {
     m_running = false;
     if (m_thread.joinable()) m_thread.join();
 
-    std::lock_guard<std::mutex> lock(m_wsMutex);
+    // Web 线程已退出，此处触碰连接列表安全
     for (auto c : m_wsConnections) {
         mg_ws_send(c, "", 0, WEBSOCKET_OP_CLOSE);
     }
@@ -118,15 +116,29 @@ bool WebServer::serverThreadCB(void* pParam) {
 bool WebServer::serverThreadFunc() {
     while (m_running) {
         mg_mgr_poll(&m_mgr, 200);
+        // 仅在本线程（poll 间隙）发送，避免跨线程操作 mongoose 连接
+        flushPending();
     }
     return true;
 }
 
-void WebServer::broadcast(const std::string& text) {
-    std::lock_guard<std::mutex> lock(m_wsMutex);
+void WebServer::flushPending() {
+    std::string text;
+    {
+        std::lock_guard<std::mutex> lock(m_pendingMutex);
+        text = std::move(m_pending);
+        m_pending.clear();
+    }
+    if (text.empty()) return;
     for (auto c : m_wsConnections) {
         mg_ws_send(c, text.c_str(), text.size(), WEBSOCKET_OP_TEXT);
     }
 }
 
+void WebServer::broadcast(const std::string& text) {
+    // 只投递到队列，实际发送在 Web 线程 flushPending() 中完成
+    std::lock_guard<std::mutex> lock(m_pendingMutex);
+    m_pending = text;
+}
+
 } // namespace ccu