已按“实验成绩独立管理”完成修改。

每个实验项目独立建成绩单，支持评分项、参与状态、补做次数、安全违规、报告地址和教师评语。
流程为：录入 → 学院审核 → 教务发布；学生只能查看已发布成绩。
自主预约实验支持同步有效预约名单，已评分记录不会被误删。
课程成绩可将已发布实验成绩汇总为快照导入指定分项；导入后锁定，不能手工篡改。
实验项目成绩不完整时，对应课程分项保持空白，不按 0 分处理。
一级“实验管理”菜单下增加“项目与场次”“实验成绩”；学生端增加“实验安排”“实验成绩”。
已生成 MySQL 正式迁移及 SQLite 开发迁移，尚未操作生产数据库。
界面采用“实验项目 → 独立评分 → 审核发布”工作台设计。

src/Jiaowu.Api/Domain/Academic/ExperimentEntities.cs

@@ -19,6 +19,7 @@ public sealed class ExperimentProject : EntityBase
     public DateTime? ClosedAt { get; set; }
     public ICollection<ExperimentSession> Sessions { get; set; } = [];
     public ICollection<ExperimentBooking> Bookings { get; set; } = [];
+    public ExperimentGradeSheet? GradeSheet { get; set; }
 }
 
 public sealed class ExperimentSession : EntityBase

src/Jiaowu.Api/Domain/Academic/ExperimentGradeEntities.cs

@@ -0,0 +1,92 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ExperimentGradeSheet : EntityBase
+{
+    public Guid ExperimentProjectId { get; set; }
+    public ExperimentProject? ExperimentProject { get; set; }
+    public decimal ContributionWeight { get; set; } = 1;
+    public decimal PassScore { get; set; } = 60;
+    public ExperimentGradeSheetStatus Status { get; set; } =
+        ExperimentGradeSheetStatus.Draft;
+    public string? ReviewComment { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public DateTime? ReviewedAt { get; set; }
+    public DateTime? PublishedAt { get; set; }
+    public ICollection<ExperimentGradeItem> Items { get; set; } = [];
+    public ICollection<ExperimentGradeRecord> Records { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItem : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public required string Name { get; set; }
+    public ExperimentGradeItemKind Kind { get; set; } =
+        ExperimentGradeItemKind.Other;
+    public decimal Weight { get; set; }
+    public int SortOrder { get; set; }
+    public ICollection<ExperimentGradeItemScore> Scores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeRecord : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public Guid? ExperimentSessionId { get; set; }
+    public ExperimentSession? ExperimentSession { get; set; }
+    public ExperimentParticipationStatus ParticipationStatus { get; set; } =
+        ExperimentParticipationStatus.Pending;
+    public decimal? TotalScore { get; set; }
+    public bool? IsPassed { get; set; }
+    public bool SafetyViolation { get; set; }
+    public int AttemptNumber { get; set; } = 1;
+    public string? SubmissionReference { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public bool IsLate { get; set; }
+    public string? TeacherComment { get; set; }
+    public ICollection<ExperimentGradeItemScore> ItemScores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItemScore
+{
+    public Guid ExperimentGradeRecordId { get; set; }
+    public ExperimentGradeRecord? ExperimentGradeRecord { get; set; }
+    public Guid ExperimentGradeItemId { get; set; }
+    public ExperimentGradeItem? ExperimentGradeItem { get; set; }
+    public decimal? Score { get; set; }
+    public string? Comment { get; set; }
+}
+
+public enum ExperimentGradeSheetStatus
+{
+    Draft = 1,
+    Submitted = 2,
+    Approved = 3,
+    Published = 4,
+    Returned = 5
+}
+
+public enum ExperimentGradeItemKind
+{
+    Operation = 1,
+    Report = 2,
+    Result = 3,
+    Defense = 4,
+    Attendance = 5,
+    Safety = 6,
+    Other = 7
+}
+
+public enum ExperimentParticipationStatus
+{
+    Pending = 1,
+    Completed = 2,
+    Absent = 3,
+    Excused = 4,
+    Makeup = 5,
+    Exempt = 6
+}

src/Jiaowu.Api/Domain/Academic/GradeEntities.cs

@@ -24,6 +24,9 @@ public sealed class GradeItem : EntityBase
     public required string Name { get; set; }
     public decimal Weight { get; set; }
     public int SortOrder { get; set; }
+    public GradeItemSourceType SourceType { get; set; } =
+        GradeItemSourceType.Manual;
+    public DateTime? SourceSnapshotAt { get; set; }
     public ICollection<GradeItemScore> Scores { get; set; } = [];
 }
 
@@ -68,3 +71,9 @@ public enum GradeExamStatus
     Exempt = 4,
     Makeup = 5
 }
+
+public enum GradeItemSourceType
+{
+    Manual = 1,
+    ExperimentSummary = 2
+}