Improve live S300 update responsiveness

lib/core/bluetooth/bt_poller.dart

@@ -8,7 +8,7 @@ enum EcuType { s300, kpro }
 
 /// Sends the ECU request byte every [pollingInterval] ms,
 /// accumulates raw bytes into 128-byte frames, validates NEG8,
-/// and emits valid frames on [frameStream].
+/// and emits the newest usable frame on [frameStream].
 class BtPoller {
   final BtService _service;
   EcuType ecuType;
@@ -34,7 +34,7 @@ class BtPoller {
   BtPoller(
     this._service, {
     this.ecuType = EcuType.s300,
-    this.pollingInterval = const Duration(milliseconds: 100),
+    this.pollingInterval = const Duration(milliseconds: 50),
   });
 
   void start() {
@@ -66,6 +66,8 @@ class BtPoller {
     // Extract as many 128-byte frames as possible.
     // Frame start sync: first byte should be 0x1B (header marker).
     // If we have a misaligned buffer, scan forward.
+    Uint8List? latestUsableFrame;
+
     while (_rxBuf.length >= 128) {
       // Scan for 0x1B frame header
       int startIdx = 0;
@@ -91,7 +93,7 @@ class BtPoller {
       if (canUseFrame) {
         if (!checksumOk) droppedFrames++;
         validFrames++;
-        _frameController.add(frame);
+        latestUsableFrame = frame;
         _rxBuf.removeRange(0, startIdx + 128);
       } else {
         // Bad checksum — skip this byte and try again
@@ -99,6 +101,10 @@ class BtPoller {
         _rxBuf.removeRange(0, startIdx + 1);
       }
     }
+
+    if (latestUsableFrame != null) {
+      _frameController.add(latestUsableFrame);
+    }
   }
 
   void stop() {

lib/core/providers/settings_provider.dart

@@ -7,7 +7,7 @@ class AppSettings {
 
   const AppSettings({
     this.ecuType = EcuType.s300,
-    this.pollingInterval = const Duration(milliseconds: 100),
+    this.pollingInterval = const Duration(milliseconds: 50),
   });
 
   AppSettings copyWith({EcuType? ecuType, Duration? pollingInterval}) =>
@@ -25,7 +25,6 @@ class SettingsNotifier extends StateNotifier<AppSettings> {
       state = state.copyWith(pollingInterval: d);
 }
 
-final settingsProvider =
-    StateNotifierProvider<SettingsNotifier, AppSettings>(
+final settingsProvider = StateNotifierProvider<SettingsNotifier, AppSettings>(
   (ref) => SettingsNotifier(),
 );

lib/ui/screens/settings/settings_screen.dart

@@ -27,11 +27,9 @@ class SettingsScreen extends ConsumerWidget {
             leading: Icon(Icons.bluetooth, color: colors.accent),
             title: const Text('Bluetooth Device'),
             subtitle: Text(
-              bt.isConnected
-                  ? 'Connected: ${bt.deviceName}'
-                  : 'Not connected',
-              style: TextStyle(
-                  color: bt.isConnected ? Colors.green : Colors.grey),
+              bt.isConnected ? 'Connected: ${bt.deviceName}' : 'Not connected',
+              style:
+                  TextStyle(color: bt.isConnected ? Colors.green : Colors.grey),
             ),
             trailing: bt.isConnected
                 ? TextButton(
@@ -47,8 +45,7 @@ class SettingsScreen extends ConsumerWidget {
                 ? null
                 : () => Navigator.push(
                       context,
-                      MaterialPageRoute(
-                          builder: (_) => const BtPickerScreen()),
+                      MaterialPageRoute(builder: (_) => const BtPickerScreen()),
                     ),
           ),
           const Divider(height: 1, color: Colors.white10),
@@ -63,8 +60,7 @@ class SettingsScreen extends ConsumerWidget {
             groupValue: settings.ecuType,
             activeColor: colors.accent,
             onChanged: (v) {
-              if (v != null)
-                ref.read(settingsProvider.notifier).setEcuType(v);
+              if (v != null) ref.read(settingsProvider.notifier).setEcuType(v);
             },
           ),
           RadioListTile<EcuType>(
@@ -75,15 +71,14 @@ class SettingsScreen extends ConsumerWidget {
             groupValue: settings.ecuType,
             activeColor: colors.accent,
             onChanged: (v) {
-              if (v != null)
-                ref.read(settingsProvider.notifier).setEcuType(v);
+              if (v != null) ref.read(settingsProvider.notifier).setEcuType(v);
             },
           ),
           const Divider(height: 1, color: Colors.white10),
 
           // ── Polling Interval ─────────────────────────────────────
           _SectionHeader('POLLING INTERVAL'),
-          ...[50, 100, 200].map((ms) => RadioListTile<int>(
+          ...[20, 50, 100, 200].map((ms) => RadioListTile<int>(
                 title: Text('${ms}ms  (~${(1000 / ms).round()} Hz)'),
                 value: ms,
                 groupValue: settings.pollingInterval.inMilliseconds,