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/providers/ai_consent_provider.dart

@@ -0,0 +1,93 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import 'auth_provider.dart' show localDbProvider;
+
+const aiConsentVersion = 'ai-data-consent-v1';
+
+class AiConsentState {
+  final bool isLoading;
+  final bool isSaving;
+  final bool granted;
+  final String? userId;
+  final String? error;
+
+  const AiConsentState({
+    this.isLoading = true,
+    this.isSaving = false,
+    this.granted = false,
+    this.userId,
+    this.error,
+  });
+}
+
+final aiConsentProvider = NotifierProvider<AiConsentNotifier, AiConsentState>(
+  AiConsentNotifier.new,
+);
+
+class AiConsentNotifier extends Notifier<AiConsentState> {
+  @override
+  AiConsentState build() => const AiConsentState();
+
+  String _key(String userId) => '$aiConsentVersion:$userId';
+
+  Future<void> load(String userId) async {
+    state = AiConsentState(isLoading: true, userId: userId);
+    try {
+      final value = await ref.read(localDbProvider).read(_key(userId));
+      state = AiConsentState(
+        isLoading: false,
+        granted: value == 'granted',
+        userId: userId,
+      );
+    } catch (_) {
+      state = AiConsentState(
+        isLoading: false,
+        userId: userId,
+        error: '授权状态加载失败，请重试',
+      );
+    }
+  }
+
+  Future<bool> grant(String userId) async {
+    state = AiConsentState(
+      isLoading: false,
+      isSaving: true,
+      granted: state.granted,
+      userId: userId,
+    );
+    try {
+      await ref.read(localDbProvider).write(_key(userId), 'granted');
+      state = AiConsentState(isLoading: false, granted: true, userId: userId);
+      return true;
+    } catch (_) {
+      state = AiConsentState(
+        isLoading: false,
+        userId: userId,
+        error: '授权保存失败，请稍后重试',
+      );
+      return false;
+    }
+  }
+
+  Future<bool> revoke(String userId) async {
+    state = AiConsentState(
+      isLoading: false,
+      isSaving: true,
+      granted: state.granted,
+      userId: userId,
+    );
+    try {
+      await ref.read(localDbProvider).delete(_key(userId));
+      state = AiConsentState(isLoading: false, granted: false, userId: userId);
+      return true;
+    } catch (_) {
+      state = AiConsentState(
+        isLoading: false,
+        granted: true,
+        userId: userId,
+        error: '撤回授权失败，请稍后重试',
+      );
+      return false;
+    }
+  }
+}