feat: AI 意图路由/草稿存储 + Prompts 模块化 + UI 视觉统一 + AI 同意门 + 资源更新

后端:
- 新增 ai_intent_router 意图路由
- 新增 AiEntryDraft 草稿存储 + EF 迁移
- 新增 Prompts 模块化（global/modules/rag/router）
- AI Agent handlers 扩展

前端:
- 新增 AI 同意门 (ai_consent_gate/provider/details_page)
- HealthMetricVisuals 视觉统一
- 设备扫描/管理页面优化
- agent 插图替换 + 趋势指标图标

配置:
- DeepSeek 模型改 deepseek-v4-flash
- .gitignore 加 artifacts/audit
- build.gradle.kts 签名配置调整

health_app/lib/pages/device/device_scan_page.dart

@@ -27,14 +27,10 @@ class DeviceScanPage extends ConsumerStatefulWidget {
 
 class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
     with SingleTickerProviderStateMixin {
-  static const _visibleDeviceWindow = Duration(seconds: 12);
-
   final _results = <ScanResult>[];
   StreamSubscription<List<ScanResult>>? _scanSub;
   Timer? _scanStopTimer;
-  Timer? _resultPruneTimer;
   String? _connectingId;
-  DateTime? _scanStartedAt;
   bool _scanning = false;
 
   late final AnimationController _pulseCtrl;
@@ -59,7 +55,6 @@ class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
   void dispose() {
     _pulseCtrl.dispose();
     _scanStopTimer?.cancel();
-    _resultPruneTimer?.cancel();
     _scanSub?.cancel();
     unawaited(FlutterBluePlus.stopScan());
     unawaited(ref.read(healthBleServiceProvider).disconnect());
@@ -99,7 +94,6 @@ class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
     try {
       await FlutterBluePlus.stopScan();
     } catch (_) {}
-    _scanStartedAt = DateTime.now();
     await _scanSub?.cancel();
     _scanSub = FlutterBluePlus.onScanResults.listen(_onScanResults);
     await FlutterBluePlus.startScan(
@@ -112,38 +106,24 @@ class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
     _scanStopTimer = Timer(const Duration(seconds: 30), () {
       if (mounted) setState(() => _scanning = false);
     });
-    _resultPruneTimer?.cancel();
-    _resultPruneTimer = Timer.periodic(const Duration(seconds: 1), (_) {
-      if (!mounted || _connectingId != null) return;
-      final pruned = _visibleResults(_results);
-      if (_sameResults(_results, pruned)) return;
-      setState(() {
-        _results
-          ..clear()
-          ..addAll(pruned);
-      });
-    });
   }
 
   void _onScanResults(List<ScanResult> list) {
     if (!mounted || _connectingId != null) return;
-    final scanStartedAt = _scanStartedAt;
-    if (scanStartedAt == null) return;
     final boundDevices = ref.read(omronDeviceProvider).devices;
-    final supported = list.where((result) {
-      if (result.timeStamp.isBefore(scanStartedAt)) return false;
-      if (!result.advertisementData.connectable) return false;
-      if (DateTime.now().difference(result.timeStamp) > _visibleDeviceWindow) {
-        return false;
-      }
-      if (!HealthBleService.isSupportedHealthDevice(result)) return false;
+    final candidates = list.where((result) {
+      // Keep the result in the list first. Many health devices expose their
+      // standard service only after connection, not in the advertisement.
+      // Also avoid relying on ScanResult.timeStamp/connectable here: both can
+      // be stale or conservative while a device is in communication mode.
+      if (!_looksLikeHealthDevice(result)) return false;
       return boundDevices.every(
         (device) => device.id != result.device.remoteId.toString(),
       );
     });
 
     final next = [..._results];
-    for (final result in supported) {
+    for (final result in candidates) {
       final index = next.indexWhere(
         (item) => item.device.remoteId == result.device.remoteId,
       );
@@ -163,33 +143,32 @@ class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
   }
 
   List<ScanResult> _visibleResults(List<ScanResult> results) {
-    final visible =
-        results
-            .where(
-              (result) =>
-                  DateTime.now().difference(result.timeStamp) <=
-                  _visibleDeviceWindow,
-            )
-            .toList()
-          ..sort(
-            (a, b) => a.device.remoteId.toString().compareTo(
-              b.device.remoteId.toString(),
-            ),
-          );
+    final visible = [...results]
+      ..sort(
+        (a, b) => a.device.remoteId.toString().compareTo(
+          b.device.remoteId.toString(),
+        ),
+      );
     return visible;
   }
 
+  bool _looksLikeHealthDevice(ScanResult result) {
+    if (HealthBleService.deviceTypeFromScan(result) != null) return true;
+    final name = [
+      result.advertisementData.advName,
+      result.device.platformName,
+    ].join(' ').toUpperCase();
+    return name.contains('OMRON') ||
+        name.contains('HEM') ||
+        name.contains('BLESMART') ||
+        name.contains('J735') ||
+        name.contains('BPM') ||
+        name.contains('BP');
+  }
+
   Future<void> _connectBindAndSync(ScanResult result) async {
     final remoteId = result.device.remoteId.toString();
     if (_connectingId != null) return;
-    final scanStartedAt = _scanStartedAt;
-    if (scanStartedAt == null ||
-        result.timeStamp.isBefore(scanStartedAt) ||
-        !result.advertisementData.connectable ||
-        DateTime.now().difference(result.timeStamp) > _visibleDeviceWindow) {
-      AppToast.show(context, '设备已离线，请重新进入通信状态', type: AppToastType.warning);
-      return;
-    }
     if (ref.read(omronDeviceProvider).isBound &&
         ref.read(omronDeviceProvider).findById(remoteId) != null) {
       AppToast.show(context, '该设备已绑定', type: AppToastType.info);
@@ -348,10 +327,15 @@ class _DeviceScanPageState extends ConsumerState<DeviceScanPage>
   }
 
   Future<bool> _ensureBlePermissions() async {
-    final statuses = await [
-      Permission.bluetoothScan,
-      Permission.bluetoothConnect,
-    ].request();
+    final permissions = <Permission>[
+      if (Platform.isAndroid) Permission.bluetoothScan,
+      if (Platform.isAndroid) Permission.bluetoothConnect,
+      // Android 11 and below require a location runtime permission for BLE
+      // scanning. Requesting it here also keeps older devices from silently
+      // returning an empty scan stream.
+      if (Platform.isAndroid) Permission.locationWhenInUse,
+    ];
+    final statuses = await permissions.request();
     final granted = statuses.values.every((status) => status.isGranted);
     if (granted) return true;
     if (!mounted) return false;