feat: AI 对话附件上下文解析 + 历史会话归档 + 多页面 UI 重构

- 后端: 新增 AttachmentContextBuilder 解析图片/PDF 摘要并拼入 LLM 上下文; ai_chat_endpoints 扩展附件接口; 新增 ReportAnalysisService
- 前端: 新增历史会话页与 conversation_history_provider; chat 链路支持附件展示与回放
- UI: 重构 medication_checkin / notification_center / profile / health_drawer 等多页面
- 配置: api_client baseUrl 适配当前 WiFi IP

health_app/lib/pages/home/home_page.dart

@@ -21,7 +21,8 @@ class HomePage extends ConsumerStatefulWidget {
   ConsumerState<HomePage> createState() => _HomePageState();
 }
 
-class _HomePageState extends ConsumerState<HomePage> {
+class _HomePageState extends ConsumerState<HomePage>
+    with WidgetsBindingObserver {
   final _textCtrl = TextEditingController();
   final _scrollCtrl = ScrollController();
   final _focusNode = FocusNode();
@@ -32,6 +33,7 @@ class _HomePageState extends ConsumerState<HomePage> {
   @override
   void initState() {
     super.initState();
+    WidgetsBinding.instance.addObserver(this);
     WidgetsBinding.instance.addPostFrameCallback(
       (_) => ref.invalidate(notificationUnreadCountProvider),
     );
@@ -41,8 +43,19 @@ class _HomePageState extends ConsumerState<HomePage> {
     );
   }
 
+  @override
+  void didChangeMetrics() {
+    // 键盘动画期间每帧都会回调，让列表底部始终贴住输入区上沿
+    if (!_focusNode.hasFocus) return;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted || !_scrollCtrl.hasClients) return;
+      _scrollCtrl.jumpTo(_scrollCtrl.position.maxScrollExtent);
+    });
+  }
+
   @override
   void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
     _notificationTimer?.cancel();
     _textCtrl.dispose();
     _scrollCtrl.dispose();
@@ -102,16 +115,18 @@ class _HomePageState extends ConsumerState<HomePage> {
     return Scaffold(
       backgroundColor: const Color(0xFFFFFCFF),
       drawer: const HealthDrawer(),
-      drawerEdgeDragWidth: MediaQuery.of(context).size.width * 0.35,
+      drawerEdgeDragWidth: MediaQuery.sizeOf(context).width * 0.65,
       body: AppBackground(
         safeArea: true,
         child: Column(
           children: [
             _buildHeader(user),
             Expanded(
-              child: ChatMessagesView(
-                scrollCtrl: _scrollCtrl,
-                messages: chatState.messages,
+              child: RepaintBoundary(
+                child: ChatMessagesView(
+                  scrollCtrl: _scrollCtrl,
+                  messages: chatState.messages,
+                ),
               ),
             ),
             _buildBottomBar(context),
@@ -472,17 +487,29 @@ class _HomePageState extends ConsumerState<HomePage> {
               ),
               ListTile(
                 leading: const Icon(
-                  Icons.file_open_outlined,
+                  Icons.picture_as_pdf_outlined,
                   color: AppColors.primary,
                 ),
-                title: const Text('传文件'),
+                title: const Text('上传 PDF'),
                 onTap: () async {
                   Navigator.pop(ctx);
-                  final result = await FilePicker.platform.pickFiles();
-                  if (result != null && result.files.isNotEmpty) {
-                    _textCtrl.text = '[文件已选择] ${result.files.first.name}';
-                    if (mounted) setState(() {});
-                  }
+                  final result = await FilePicker.platform.pickFiles(
+                    type: FileType.custom,
+                    allowedExtensions: ['pdf'],
+                    withData: false,
+                  );
+                  if (result == null || result.files.isEmpty) return;
+                  final pdfFile = result.files.first;
+                  final path = pdfFile.path;
+                  if (path == null || path.isEmpty) return;
+                  // 上传 + 让 AI 看 PDF 内容
+                  await ref.read(chatProvider.notifier).sendPdf(
+                    path,
+                    pdfFile.name,
+                    _textCtrl.text.trim(),
+                  );
+                  _textCtrl.clear();
+                  if (mounted) setState(() {});
                 },
               ),
             ],