fix: header shows the real last-used model, not always flash

Fix: ProxyServer now increments _modelVersion each time _currentModel
changes.  TUI refresh loop checks _proxy.modelVersion against
_lastModelVersion on every 1-second tick, so the header and the
Proxy page immediately reflect the model from the most recent chat
completion request, regardless of which info page is active.

Also show the current model directly on the Proxy page content.

Author: Khip01

lib/src/server/proxy.dart

@@ -12,9 +12,11 @@ class ProxyServer {
   final ConfigStore configStore;
   bool _running = false;
   String _currentModel = 'deepseek/deepseek-v4-flash';
+  int _modelVersion = 0;
 
   bool get isRunning => _running;
   String get currentModel => _currentModel;
+  int get modelVersion => _modelVersion;
 
   ProxyServer({required this.accountStore, required this.configStore});
 
@@ -91,6 +93,7 @@ class ProxyServer {
       final tools = _toWireTools(openaiReq['tools']);
 
       _currentModel = model;
+      _modelVersion++;
 
       if (stream) {
         await _proxyStreaming(

lib/src/tui/app.dart

@@ -48,6 +48,7 @@ class AppState extends State<CmdBridgeApp> {
   bool _foregroundRefresh = true;
   DateTime? _lastAutoRefreshAt;
   int _lastLogVersion = -1;
+  int _lastModelVersion = 0;
 
   final _portCtrl = TextEditingController();
   bool _portScanDone = false;
@@ -120,6 +121,12 @@ class AppState extends State<CmdBridgeApp> {
       return;
     }
 
+    if (_lastModelVersion != _proxy.modelVersion) {
+      _lastModelVersion = _proxy.modelVersion;
+      setState(() {});
+      return;
+    }
+
     if (_infoPage == _InfoPage.proxy) {
       setState(() {});
       return;
@@ -1061,6 +1068,7 @@ class AppState extends State<CmdBridgeApp> {
         add('Proxy Configuration', Colors.cyan);
         add('');
         add('Status:      ${_proxy.isRunning ? "Running" : "Stopped"}');
+        add('Last Model:  ${_proxy.currentModel}');
         add('Port:        ${_config.config.serverPort}');
         add('Listen:      http://127.0.0.1:${_config.config.serverPort}');
         add('API URL:     ${_config.config.apiBaseUrl}');