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

backend/src/Health.Application/Reports/ReportService.cs

@@ -8,10 +8,10 @@ public sealed class ReportService(
     IReportFileStorage fileStorage,
     IReportAnalysisQueue queue) : IReportService
 {
-    private const long MaxReportImageBytes = 10 * 1024 * 1024;
+    private const long MaxReportFileBytes = 20 * 1024 * 1024;
     private static readonly HashSet<string> AllowedExtensions = new(StringComparer.OrdinalIgnoreCase)
     {
-        ".jpg", ".jpeg", ".png", ".webp"
+        ".jpg", ".jpeg", ".png", ".webp", ".pdf"
     };
 
     private readonly IReportRepository _reports = reports;
@@ -35,12 +35,12 @@ public sealed class ReportService(
         if (file.Length <= 0)
             return Fail(400, "未上传文件");
 
-        if (file.Length > MaxReportImageBytes)
-            return Fail(400, "报告图片不能超过 10MB，请压缩后重新上传");
+        if (file.Length > MaxReportFileBytes)
+            return Fail(400, "报告文件不能超过 20MB，请压缩后重新上传");
 
         var ext = Path.GetExtension(file.FileName).ToLowerInvariant();
         if (!AllowedExtensions.Contains(ext))
-            return Fail(400, "目前仅支持上传 JPG、PNG、WEBP 格式的报告图片");
+            return Fail(400, "目前支持上传 JPG、PNG、WEBP 图片或 PDF 报告");
 
         var storedFile = await _fileStorage.SaveAsync(file, ext, ct);
         var report = new Report
@@ -48,7 +48,7 @@ public sealed class ReportService(
             Id = Guid.NewGuid(),
             UserId = userId,
             FileUrl = storedFile.FileUrl,
-            FileType = ReportFileType.Image,
+            FileType = ext == ".pdf" ? ReportFileType.Pdf : ReportFileType.Image,
             Category = ReportCategory.Other,
             Status = ReportStatus.Analyzing,
             AiSummary = null,