fix: lazy-load @system.interconnect so simulator renders without the module

src/common/bridge.js

@@ -1,8 +1,21 @@
 // DSHWatch bridge: @system.interconnect wrapper.
 // Sends/receives JSON envelopes to the DSHWatch phone APP over the Vela BLE channel.
-// Protocol per DSHWatch_Server/docs/PROTOCOL.md.
+// The interconnect module is loaded lazily (guarded) so the app can still render
+// on simulators/environments where the system module is unavailable.
 
-import interconnect from '@system.interconnect'
+let interconnectModule = null;
+let interconnectTried = false;
+
+function loadInterconnect() {
+  if (interconnectTried) return interconnectModule;
+  interconnectTried = true;
+  try {
+    interconnectModule = require('@system.interconnect');
+  } catch (e) {
+    interconnectModule = null;
+  }
+  return interconnectModule;
+}
 
 let conn = null
 let seq = 0
@@ -10,6 +23,8 @@ const listeners = new Set()
 let currentStatus = '未连接'
 
 function getConn() {
+  const interconnect = loadInterconnect();
+  if (!interconnect) return null;
   if (!conn) {
     try {
       conn = interconnect.instance()
@@ -29,7 +44,6 @@ function getConn() {
       emit('status', currentStatus)
     }
     conn.onmessage = (data) => {
-      // interconnect 回调: data.data 是手机端发来的内容
       let msg = data && data.data !== undefined ? data.data : data
       if (typeof msg === 'string') {
         try { msg = JSON.parse(msg) } catch (e) { return }