android: utun shutdown diagnostics + non-blocking stop + logreceiver doc

- instance_lite: cleanup moved to uasync thread (self-detach), events on start/stop
- udp_log: cancel_timer before uasync_destroy, flush on stop, stopping flag
- jni_bridge: fixed UDP stop order (cancel_timer → destroy → flush)
- instance_lite: u_report_unfreed_blocks at all shutdown paths
- chat_event: CHAT_EVT_SERVICE_STARTED/STOPPED for GUI notifications
- AGENTS: logreceiver section

tools/chatgui-android/libutun_lite/instance_lite.c

@@ -175,6 +175,7 @@ static void* instance_thread(void* arg) {
         IL_LOGE("utun_instance_create_from_config failed");
         uasync_destroy(g_ua, 0);
         g_ua = NULL;
+        u_report_unfreed_blocks();
         g_running = 0;
         return NULL;
     }
@@ -207,6 +208,7 @@ static void* instance_thread(void* arg) {
         g_inst = NULL;
         uasync_destroy(g_ua, 0);
         g_ua = NULL;
+        u_report_unfreed_blocks();
         g_running = 0;
         return NULL;
     }
@@ -223,12 +225,28 @@ static void* instance_thread(void* arg) {
     }
 
     g_running = 1;
+    chat_event_post(CHAT_EVT_SERVICE_STARTED, NULL, 0);
 
     while (!g_stop) {
         uasync_poll(g_ua, 100);
     }
 
-    IL_LOGI("poll loop exit");
+    IL_LOGI("poll loop exit, cleaning up");
+
+    if (g_inst) {
+        utun_instance_destroy(g_inst);
+        g_inst = NULL;
+    }
+    if (g_ua) {
+        uasync_destroy(g_ua, 0);
+        g_ua = NULL;
+    }
+    u_report_unfreed_blocks();
+    g_running = 0;
+    chat_event_post(CHAT_EVT_SERVICE_STOPPED, NULL, 0);
+    g_event_handler = NULL;
+    pthread_detach(pthread_self());
+    IL_LOGI("cleanup complete");
     return NULL;
 }
 
@@ -272,27 +290,10 @@ int instance_lite_start(const char* config_text) {
 }
 
 void instance_lite_stop(void) {
-    if (!g_running && !g_inst) return;
+    if (!g_inst && !g_running) return;
     IL_LOGI("stopping...");
-
     g_stop = 1;
     if (g_ua) uasync_wakeup(g_ua);
-    pthread_join(g_thread, NULL);
-
-    if (g_inst) {
-        etcp_router_bind(g_inst, ETCP_RT_ID_CHAT_SYNC, NULL);
-        chat_sync_destroy(g_inst);
-        chat_core_destroy(g_inst);
-        utun_instance_destroy(g_inst);
-        g_inst = NULL;
-    }
-    if (g_ua) {
-        uasync_destroy(g_ua, 0);
-        g_ua = NULL;
-    }
-    g_running = 0;
-    g_event_handler = NULL;
-    IL_LOGI("stopped");
 }
 
 int instance_lite_is_running(void) {