fix: 修复 Flutter 前端多项功能 + 后端运动计划 API

- Android 添加相机/存储权限，拍照和相册功能可用
- AI 回复支持 Markdown 渲染（加粗/表格不再显示**乱码）
- 附件按钮接线，支持拍照/相册/文件选择
- 智能体面板按钮全部接线（拍照/上传/手动录入/导航）
- 侧边栏 AI 录入后自动刷新健康数据
- 运动计划页增加创建按钮 + 打卡功能
- 后端运动计划支持 AI 创建和打卡（Tool Calling）
- 修复 CreateExercisePlanRequest JSON 反序列化

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

@@ -470,13 +470,44 @@ public static class AiChatEndpoints
     private static async Task<object> ExecuteManageExercise(AppDbContext db, Guid userId, JsonElement args)
     {
         var action = args.TryGetProperty("action", out var a) ? a.GetString()! : "query";
-        if (action != "query") return new { success = false, message = "运动计划管理暂未实现" };
+        switch (action)
+        {
+            case "create":
+                var weekStart = args.TryGetProperty("week_start_date", out var wsd) ? DateOnly.Parse(wsd.GetString()!) : DateOnly.FromDateTime(DateTime.Now);
+                var plan = new ExercisePlan { Id = Guid.NewGuid(), UserId = userId, WeekStartDate = weekStart };
+                if (args.TryGetProperty("items", out var items))
+                {
+                    foreach (var item in items.EnumerateArray())
+                    {
+                        plan.Items.Add(new ExercisePlanItem
+                        {
+                            Id = Guid.NewGuid(), DayOfWeek = item.GetProperty("day_of_week").GetInt32(),
+                            ExerciseType = item.GetProperty("exercise_type").GetString() ?? "散步",
+                            DurationMinutes = item.GetProperty("duration_minutes").GetInt32(),
+                            IsRestDay = item.TryGetProperty("is_rest_day", out var rd) && rd.GetBoolean(),
+                        });
+                    }
+                }
+                db.ExercisePlans.Add(plan);
+                await db.SaveChangesAsync();
+                return new { success = true, plan_id = plan.Id };
 
-        var plan = await db.ExercisePlans.Where(p => p.UserId == userId)
-            .OrderByDescending(p => p.WeekStartDate).FirstOrDefaultAsync();
-        if (plan == null) return new { found = false };
-        var items = await db.ExercisePlanItems.Where(i => i.PlanId == plan.Id).OrderBy(i => i.DayOfWeek).ToListAsync();
-        return new { found = true, plan_id = plan.Id, items = items.Select(i => new { i.DayOfWeek, i.ExerciseType, i.DurationMinutes, i.IsCompleted }) };
+            case "checkin":
+                var itemId = args.TryGetProperty("item_id", out var iid) ? iid.GetGuid() : Guid.Empty;
+                var exerciseItem = await db.ExercisePlanItems.FindAsync([itemId]);
+                if (exerciseItem == null) return new { success = false, message = "条目不存在" };
+                exerciseItem.IsCompleted = true;
+                exerciseItem.CompletedAt = DateTime.UtcNow;
+                await db.SaveChangesAsync();
+                return new { success = true };
+
+            default: // query
+                var existingPlan = await db.ExercisePlans.Where(p => p.UserId == userId)
+                    .OrderByDescending(p => p.WeekStartDate).FirstOrDefaultAsync();
+                if (existingPlan == null) return new { found = false };
+                var exerciseItems = await db.ExercisePlanItems.Where(i => i.PlanId == existingPlan.Id).OrderBy(i => i.DayOfWeek).ToListAsync();
+                return new { found = true, plan_id = existingPlan.Id, items = exerciseItems.Select(i => new { i.Id, i.DayOfWeek, i.ExerciseType, i.DurationMinutes, i.IsCompleted }) };
+        }
     }
 
     private static async Task<string> BuildPatientContext(AppDbContext db, Guid userId, CancellationToken ct)

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

@@ -271,5 +271,15 @@ public sealed record CreateMedicationRequest(string Name, string? Dosage, Medica
 public sealed record CreateConsultationRequest(Guid DoctorId);
 public sealed record SendMessageRequest(string Content);
 
-public sealed record CreateExercisePlanRequest(DateOnly WeekStartDate, List<ExerciseItemDto>? Items);
-public sealed record ExerciseItemDto(int DayOfWeek, string ExerciseType, int DurationMinutes, bool IsRestDay);
+public sealed class CreateExercisePlanRequest
+{
+    public DateOnly WeekStartDate { get; init; }
+    public List<ExerciseItemDto>? Items { get; init; }
+}
+public sealed class ExerciseItemDto
+{
+    public int DayOfWeek { get; init; }
+    public string ExerciseType { get; init; } = "";
+    public int DurationMinutes { get; init; }
+    public bool IsRestDay { get; init; }
+}