feat: ui rework and gear generator

lib/pages/device_details_page.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:abawo_bt_app/controller/shifter_device_telemetry.dart';
 import 'package:abawo_bt_app/model/firmware_file_selection.dart';
 import 'package:abawo_bt_app/model/shifter_types.dart';
 import 'package:abawo_bt_app/service/firmware_file_selection_service.dart';
@@ -69,6 +70,8 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
   String? _gearRatiosError;
   List<double> _gearRatios = const [];
   int _defaultGearIndex = 0;
+  bool _isDeviceTelemetryLoading = false;
+  bool _hasLoadedDeviceTelemetry = false;
 
   late final FirmwareFileSelectionService _firmwareFileSelectionService;
   FirmwareUpdateService? _firmwareUpdateService;
@@ -195,6 +198,9 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       if (!_hasLoadedGearRatios && !_isGearRatiosLoading) {
         unawaited(_loadGearRatios());
       }
+      if (!_hasLoadedDeviceTelemetry && !_isDeviceTelemetryLoading) {
+        unawaited(_loadDeviceTelemetry());
+      }
       return;
     }
     final asyncBluetooth = ref.read(bluetoothProvider);
@@ -238,6 +244,7 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       _shifterService = service;
     });
     unawaited(_loadGearRatios());
+    unawaited(_loadDeviceTelemetry());
   }
 
   Future<void> _showPairingRecoveryDialog() async {
@@ -276,6 +283,8 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     await _disposeFirmwareUpdateService();
     await _shifterService?.dispose();
     _shifterService = null;
+    _isDeviceTelemetryLoading = false;
+    _hasLoadedDeviceTelemetry = false;
   }
 
   Future<void> _disposeFirmwareUpdateService() async {
@@ -285,6 +294,34 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
     _firmwareUpdateService = null;
   }
 
+  Future<void> _loadDeviceTelemetry({bool force = false}) async {
+    final shifter = _shifterService;
+    if (shifter == null || _isDeviceTelemetryLoading) {
+      return;
+    }
+    if (_hasLoadedDeviceTelemetry && !force) {
+      return;
+    }
+
+    _isDeviceTelemetryLoading = true;
+    final result = await shifter.readDeviceTelemetry();
+    if (!mounted) {
+      return;
+    }
+
+    _isDeviceTelemetryLoading = false;
+    if (result.isErr()) {
+      _hasLoadedDeviceTelemetry = false;
+      return;
+    }
+
+    ref.read(shifterDeviceTelemetryCacheProvider.notifier).upsert(
+          widget.deviceAddress,
+          result.unwrap(),
+        );
+    _hasLoadedDeviceTelemetry = true;
+  }
+
   Future<void> _loadGearRatios() async {
     final shifter = _shifterService;
     if (shifter == null || _isGearRatiosLoading || _isFirmwareUpdateBusy) {
@@ -539,6 +576,11 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
         _firmwareUserMessage = result.unwrapErr().toString();
       }
     });
+
+    if (result.isOk()) {
+      _hasLoadedDeviceTelemetry = false;
+      unawaited(_loadDeviceTelemetry(force: true));
+    }
   }
 
   String _dfuPhaseText(DfuUpdateState state) {
@@ -1208,6 +1250,11 @@ Widget _buildDeviceOverviewCard(
   required CentralStatus? status,
 }) {
   final asyncSavedDevices = ref.watch(nConnectedDevicesProvider);
+  final telemetry = ref.watch(
+    shifterDeviceTelemetryCacheProvider.select(
+      (cache) => cache[deviceAddress],
+    ),
+  );
 
   return asyncSavedDevices.when(
     data: (devices) {
@@ -1229,12 +1276,11 @@ Widget _buildDeviceOverviewCard(
         );
       }
 
-      // TODO(yannik): Replace these overview placeholder metrics with actual
-      // battery, signal, and firmware values once the device exposes them.
       return _DeviceOverviewCard(
         device: currentDeviceData,
         connectionStatus: connectionStatus,
         status: status,
+        telemetry: telemetry,
       );
     },
     loading: () => const Card(
@@ -1257,11 +1303,13 @@ class _DeviceOverviewCard extends StatelessWidget {
     required this.device,
     required this.connectionStatus,
     required this.status,
+    required this.telemetry,
   });
 
   final ConnectedDevice device;
   final ConnectionStatus connectionStatus;
   final CentralStatus? status;
+  final ShifterDeviceTelemetry? telemetry;
 
   @override
   Widget build(BuildContext context) {
@@ -1317,27 +1365,27 @@ class _DeviceOverviewCard extends StatelessWidget {
             ),
             const SizedBox(height: 18),
             Row(
-              children: const [
+              children: [
                 Expanded(
                   child: _OverviewMetricTile(
                     label: 'Battery',
-                    value: '--',
+                    value: telemetry?.batteryLabel ?? '--',
                     icon: Icons.battery_charging_full_rounded,
                   ),
                 ),
-                SizedBox(width: 10),
-                Expanded(
+                const SizedBox(width: 10),
+                const Expanded(
                   child: _OverviewMetricTile(
                     label: 'Signal',
                     value: 'Ready',
                     icon: Icons.signal_cellular_alt_rounded,
                   ),
                 ),
-                SizedBox(width: 10),
+                const SizedBox(width: 10),
                 Expanded(
                   child: _OverviewMetricTile(
                     label: 'Firmware',
-                    value: '--',
+                    value: telemetry?.firmwareLabel ?? '--',
                     icon: Icons.memory_rounded,
                   ),
                 ),