fix: VLM识别修复 + 饮食CRUD + 侧边栏美化 + UI优化

- VLM: ChatMessage.Content string→object, 修复视觉content双重序列化
- 饮食: diet/medication端点 record→手动JSON解析, 修复循环引用
- 饮食记录: 左滑删除 + 去评分 + AI饮食评语(DeepSeek)
- 侧边栏: 功能区统一Row+Expanded, 服务包compact模式
- 历史对话: 点击加载历史消息
- 登录页: 居中布局, 去底部空白
- UI: 主色加深#6C5CE7, maxWidth:1024防图片超大

backend/src/Health.WebApi/Endpoints/medication_endpoints.cs

@@ -13,27 +13,52 @@ public static class MedicationEndpoints
             return Results.Ok(new { code = 0, data = meds, message = (string?)null });
         });
 
-        group.MapPost("/", async (CreateMedicationRequest req, HttpContext http, AppDbContext db, CancellationToken ct) =>
+        group.MapPost("/", async (HttpRequest request, HttpContext http, AppDbContext db, CancellationToken ct) =>
         {
             var userId = GetUserId(http);
+            request.EnableBuffering();
+            using var reader = new StreamReader(request.Body);
+            var body = await reader.ReadToEndAsync(ct);
+            request.Body.Position = 0;
+            using var json = JsonDocument.Parse(body);
+            var root = json.RootElement;
             var med = new Medication
             {
-                Id = Guid.NewGuid(), UserId = userId, Name = req.Name, Dosage = req.Dosage,
-                Frequency = req.Frequency, TimeOfDay = req.TimeOfDay ?? [],
-                StartDate = req.StartDate, EndDate = req.EndDate, IsActive = true, Source = req.Source,
+                Id = Guid.NewGuid(), UserId = userId,
+                Name = root.GetProperty("name").GetString()!,
+                Dosage = root.TryGetProperty("dosage", out var dg) ? dg.GetString() : null,
+                Frequency = Enum.TryParse<MedicationFrequency>(root.TryGetProperty("frequency", out var f) ? f.GetString() : "Daily", out var freq) ? freq : MedicationFrequency.Daily,
+                Source = Enum.TryParse<MedicationSource>(root.TryGetProperty("source", out var s) ? s.GetString() : "Manual", out var src) ? src : MedicationSource.Manual,
+                IsActive = true,
             };
+            if (root.TryGetProperty("timeOfDay", out var tod))
+                med.TimeOfDay = tod.EnumerateArray().Select(t => TimeOnly.Parse(t.GetString()!)).ToList();
+            if (root.TryGetProperty("startDate", out var sd))
+                med.StartDate = DateOnly.TryParse(sd.GetString(), out var d) ? d : null;
+            if (root.TryGetProperty("endDate", out var ed))
+                med.EndDate = DateOnly.TryParse(ed.GetString(), out var d2) ? d2 : null;
             db.Medications.Add(med);
             await db.SaveChangesAsync(ct);
             return Results.Ok(new { code = 0, data = new { med.Id }, message = (string?)null });
         });
 
-        group.MapPut("/{id:guid}", async (Guid id, CreateMedicationRequest req, HttpContext http, AppDbContext db, CancellationToken ct) =>
+        group.MapPut("/{id:guid}", async (Guid id, HttpRequest request, HttpContext http, AppDbContext db, CancellationToken ct) =>
         {
             var userId = GetUserId(http);
             var med = await db.Medications.FirstOrDefaultAsync(m => m.Id == id && m.UserId == userId, ct);
             if (med == null) return Results.Ok(new { code = 40004, message = "不存在" });
-            med.Name = req.Name; med.Dosage = req.Dosage; med.Frequency = req.Frequency;
-            med.TimeOfDay = req.TimeOfDay ?? med.TimeOfDay; med.StartDate = req.StartDate; med.EndDate = req.EndDate;
+            request.EnableBuffering();
+            using var reader = new StreamReader(request.Body);
+            var body = await reader.ReadToEndAsync(ct);
+            request.Body.Position = 0;
+            using var json = JsonDocument.Parse(body);
+            var root = json.RootElement;
+            if (root.TryGetProperty("name", out var n)) med.Name = n.GetString()!;
+            if (root.TryGetProperty("dosage", out var dg2)) med.Dosage = dg2.GetString();
+            if (root.TryGetProperty("frequency", out var f2) && Enum.TryParse<MedicationFrequency>(f2.GetString(), out var freq2)) med.Frequency = freq2;
+            if (root.TryGetProperty("timeOfDay", out var tod2)) med.TimeOfDay = tod2.EnumerateArray().Select(t => TimeOnly.Parse(t.GetString()!)).ToList();
+            if (root.TryGetProperty("startDate", out var sd2) && DateOnly.TryParse(sd2.GetString(), out var d3)) med.StartDate = d3;
+            if (root.TryGetProperty("endDate", out var ed2) && DateOnly.TryParse(ed2.GetString(), out var d4)) med.EndDate = d4;
             med.UpdatedAt = DateTime.UtcNow;
             await db.SaveChangesAsync(ct);
             return Results.Ok(new { code = 0, data = new { success = true }, message = (string?)null });
@@ -88,4 +113,3 @@ public static class MedicationEndpoints
         Guid.TryParse(http.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value, out var id) ? id : Guid.Empty;
 }
 
-public sealed record CreateMedicationRequest(string Name, string? Dosage, MedicationFrequency Frequency, List<TimeOnly>? TimeOfDay, DateOnly? StartDate, DateOnly? EndDate, MedicationSource Source);