feat: implement Sensor detail screen

lib/features/sensors/sensor_detail_screen.dart

@@ -2,26 +2,64 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 
+import '../../domain/models/sensor.dart';
 import '../../providers.dart';
 
-class SensorDetailScreen extends ConsumerWidget {
+class SensorDetailScreen extends ConsumerStatefulWidget {
   const SensorDetailScreen({super.key, required this.sensorId});
 
   final String sensorId;
 
   @override
-  Widget build(BuildContext context, WidgetRef ref) {
+  ConsumerState<SensorDetailScreen> createState() => _SensorDetailScreenState();
-    // TODO: fetch sensor via sensorRepositoryProvider.getSensor(sensorId).
+}
+
+class _SensorDetailScreenState extends ConsumerState<SensorDetailScreen> {
+  late final int _id = int.parse(widget.sensorId);
+
+  @override
+  Widget build(BuildContext context) {
+    final sensor = ref.watch(sensorProvider(_id));
 
     return Scaffold(
-      appBar: AppBar(title: Text('Sensor $sensorId')),
+      appBar: AppBar(
-      body: Padding(
+        title: Text(sensor.valueOrNull?.displayName ?? 'Sensor'),
+      ),
+      body: sensor.when(
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (e, _) => Center(child: Text(e.toString())),
+        data: (s) => _Body(sensor: s, id: _id, sensorId: widget.sensorId),
+      ),
+    );
+  }
+}
+
+class _Body extends ConsumerWidget {
+  const _Body({required this.sensor, required this.id, required this.sensorId});
+
+  final Sensor sensor;
+  final int id;
+  final String sensorId;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Padding(
       padding: const EdgeInsets.all(24),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.stretch,
         children: [
-            // TODO: display sensor fields (name, status, position, last seen).
+          _InfoRow(label: 'Device ID', value: sensor.sensorId),
-            const Placeholder(fallbackHeight: 200),
+          if (sensor.rssiRef != null)
+            _InfoRow(
+              label: 'RSSI reference',
+              value: '${sensor.rssiRef!.toStringAsFixed(1)} dBm',
+            ),
+          _InfoRow(
+            label: 'Floor position',
+            value: sensor.isPlaced
+                ? '(${sensor.x!.toStringAsFixed(2)}, ${sensor.y!.toStringAsFixed(2)})'
+                : 'Not placed',
+          ),
           const SizedBox(height: 24),
           OutlinedButton.icon(
             icon: const Icon(Icons.map_outlined),
@@ -32,28 +70,110 @@ class SensorDetailScreen extends ConsumerWidget {
             },
           ),
           const SizedBox(height: 12),
-            // TODO: re-provision button → show BleProvisionSheet pre-filled.
-            OutlinedButton.icon(
-              icon: const Icon(Icons.bluetooth),
-              label: const Text('Re-provision WiFi'),
-              onPressed: () {}, // TODO
-            ),
-            const SizedBox(height: 12),
           OutlinedButton.icon(
             icon: const Icon(Icons.edit_outlined),
             label: const Text('Rename'),
-              onPressed: () {}, // TODO
+            onPressed: () => _rename(context, ref),
+          ),
+          const SizedBox(height: 12),
+          OutlinedButton.icon(
+            icon: const Icon(Icons.bluetooth),
+            label: const Text('Re-provision WiFi'),
+            onPressed: () {}, // TODO: show BleProvisionSheet pre-filled
           ),
           const Spacer(),
           TextButton(
             style: TextButton.styleFrom(
               foregroundColor: Theme.of(context).colorScheme.error,
             ),
-              onPressed: () {}, // TODO: confirm dialog then delete
+            onPressed: () => _delete(context, ref),
             child: const Text('Delete sensor'),
           ),
         ],
       ),
+    );
+  }
+
+  Future<void> _rename(BuildContext context, WidgetRef ref) async {
+    final controller = TextEditingController(text: sensor.name);
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: const Text('Rename sensor'),
+        content: TextField(
+          controller: controller,
+          decoration: const InputDecoration(labelText: 'Name'),
+          autofocus: true,
+          onSubmitted: (_) => Navigator.of(ctx).pop(true),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(ctx).pop(false),
+            child: const Text('Cancel'),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.of(ctx).pop(true),
+            child: const Text('Save'),
+          ),
+        ],
+      ),
+    );
+    final name = controller.text.trim();
+    controller.dispose();
+    if (confirmed == true && name.isNotEmpty && context.mounted) {
+      await ref.read(sensorRepositoryProvider).updateSensor(id, name: name);
+      ref.invalidate(sensorProvider(id));
+      ref.invalidate(sensorsProvider);
+    }
+  }
+
+  Future<void> _delete(BuildContext context, WidgetRef ref) async {
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: const Text('Delete sensor?'),
+        content: const Text('This will unenrol the sensor from the system.'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(ctx).pop(false),
+            child: const Text('Cancel'),
+          ),
+          FilledButton(
+            style: FilledButton.styleFrom(
+              backgroundColor: Theme.of(context).colorScheme.error,
+            ),
+            onPressed: () => Navigator.of(ctx).pop(true),
+            child: const Text('Delete'),
+          ),
+        ],
+      ),
+    );
+    if (confirmed == true && context.mounted) {
+      await ref.read(sensorRepositoryProvider).deleteSensor(id);
+      ref.invalidate(sensorsProvider);
+      if (context.mounted) context.pop();
+    }
+  }
+}
+
+class _InfoRow extends StatelessWidget {
+  const _InfoRow({required this.label, required this.value});
+
+  final String label;
+  final String value;
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 8),
+      child: Row(
+        children: [
+          Expanded(
+            child: Text(label,
+                style: Theme.of(context).textTheme.bodySmall),
+          ),
+          Text(value, style: Theme.of(context).textTheme.bodyMedium),
+        ],
       ),
     );
   }