auto_socket: TCP links support, chat_sync retry on socket change, link dedup by is_tcp

src/chat/chat_sync.c

@@ -653,6 +653,20 @@ void chat_sync_destroy(struct UTUN_INSTANCE* inst) {
     u_free(cs);
 }
 
+void chat_sync_retry_channels_on_socket_change(struct UTUN_INSTANCE* inst) {
+    if (!g_cs || !g_cs->initialized || !inst->topo_groups) return;
+    for (int i = 0; i < g_cs->channel_count; i++) {
+        uint64_t gid = strtoull(g_cs->channels[i].channel_id, NULL, 10);
+        struct TOPO_GROUP* group = topo_groups_find(inst->topo_groups, gid);
+        if (!group || !group->connect) continue;
+        if (topo_group_connect_active_count(group) == 0) {
+            DEBUG_INFO(DEBUG_CATEGORY_MEMBER_SYNC, "%s: socket change — restarting connect for ch=%s (no active connections)",
+                       CS_ID, g_cs->channels[i].channel_id);
+            topo_group_connect_restart(group);
+        }
+    }
+}
+
 void chat_sync_connect_node(struct UTUN_INSTANCE* inst, uint64_t node_id) {
     (void)inst; (void)node_id;
 }