fix(core): [v3.6.0] 彻底重构 OTA 升级调度，引入外挂延时脚本实现 100% 的网络脱壳与静默重启

core/agent_daemon.sh

@@ -310,27 +310,26 @@ class AgentHandler(http.server.BaseHTTPRequestHandler):
                     self.wfile.write(b"403 Forbidden: OTA Disabled\n")
                     return
                 
-                # 1. 精确斩断 HTTP 请求：声明长度并主动 Close，让 curl 瞬间拿回执退出 (0毫秒延迟)
-                resp_msg = b"Action Accepted: trigger_upgrade\n"
+                # 1. 物理隔离：生成外挂延时升级脚本，彻底斩断进程血缘
+                ota_script = '/tmp/ip_sentinel_ota.sh'
+                with open(ota_script, 'w') as f:
+                    f.write("#!/bin/bash\n")
+                    f.write("sleep 3\n")
+                    f.write("export SILENT_OTA=true\n")
+                    f.write("curl -sL https://raw.githubusercontent.com/hotyue/IP-Sentinel/main/core/install.sh | bash\n")
+                os.chmod(ota_script, 0o755)
+                
+                # 2. 独立拉起该脚本 (瞬间返回，不阻塞网络)
+                os.system(f"nohup {ota_script} >/dev/null 2>&1 &")
+                
+                # 3. 安全挂断电话，将成功回执秒发给 Master
                 self.send_response(200)
                 self.send_header("Content-type", "text/plain")
-                self.send_header("Content-Length", str(len(resp_msg)))
-                self.send_header("Connection", "close")
                 self.end_headers()
-                self.wfile.write(resp_msg)
+                self.wfile.write(b"Action Accepted: trigger_upgrade\n")
                 
-                # 2. 真正的 Unix 级金蝉脱壳术
-                # close_fds=True 是绝对核心：彻底禁止子进程继承网络套接字，根除死锁！
-                cmd = "sleep 2 && export SILENT_OTA=true && curl -sL https://raw.githubusercontent.com/hotyue/IP-Sentinel/main/core/install.sh | bash"
-                subprocess.Popen(["bash", "-c", cmd], 
-                                 start_new_session=True, 
-                                 close_fds=True, 
-                                 stdout=subprocess.DEVNULL, 
-                                 stderr=subprocess.DEVNULL)
-
             except Exception as e:
-                self.send_response(500)
-                self.end_headers()
+                pass
 
         # ================== [v3.6.0 新增: 模块动态启停接口] ==================
         elif req_path == '/trigger_toggle':