已完成“成绩管理与学业档案”模块：

教师批量录入平时、期中、期末成绩。
自动计算总评、绩点和及格状态。
支持缺考、缓考、免修。
教师提交 → 学院审核/退回 → 校级发布。
学生只能查看正式发布成绩。
自动统计平均分、完成度、及格率和加权 GPA。
SQLite 本地增量升级和 MySQL 正式迁移均已完成。
分级权限在前后端同时校验。

src/Jiaowu.Api/Infrastructure/Persistence/DatabaseInitializer.cs

@@ -422,37 +422,84 @@ public sealed class DatabaseInitializer(
 
         await SeedDevelopmentUsersAsync(computerCollege.Id);
         await SeedDevelopmentCourseSelectionAsync();
+        await SeedDevelopmentGradesAsync();
     }
 
     private async Task SeedDevelopmentCourseSelectionAsync()
     {
-        if (await db.CourseSelectionRounds.AnyAsync())
+        if (!await db.CourseSelectionRounds.AnyAsync())
         {
-            return;
+            var term = await db.AcademicTerms.SingleAsync(x => x.IsCurrent);
+            var task = await db.TeachingTasks.SingleAsync(
+                x => x.TaskNumber == "2026-1-CS101-01");
+            var now = DateTime.UtcNow;
+            db.CourseSelectionRounds.Add(new CourseSelectionRound
+            {
+                AcademicTermId = term.Id,
+                Name = "2026—2027 学年第一学期第一轮选课",
+                StartsAt = now.AddDays(-2),
+                EndsAt = now.AddDays(14),
+                WithdrawalEndsAt = now.AddDays(21),
+                MaxCredits = 30,
+                Status = CourseSelectionRoundStatus.Open,
+                Notes = "本地开发演示轮次，可用于验证选课、退课和教学班名单。",
+                Offerings =
+                [
+                    new CourseSelectionOffering
+                    {
+                        TeachingTaskId = task.Id,
+                        Capacity = 60,
+                        IsOpenToAll = false,
+                        Notes = "面向计科 2026-1 班开放。"
+                    }
+                ]
+            });
+            await db.SaveChangesAsync();
         }
 
-        var term = await db.AcademicTerms.SingleAsync(x => x.IsCurrent);
+        var seededTask = await db.TeachingTasks.SingleAsync(
+            x => x.TaskNumber == "2026-1-CS101-01");
+        var offering = await db.CourseSelectionOfferings.FirstOrDefaultAsync(
+            x => x.TeachingTaskId == seededTask.Id);
+        var student = await db.Students.SingleAsync(x =>
+            x.StudentNumber == "202601001");
+        if (offering is not null &&
+            !await db.CourseEnrollments.AnyAsync(x =>
+                x.CourseSelectionOfferingId == offering.Id &&
+                x.StudentId == student.Id))
+        {
+            db.CourseEnrollments.Add(new CourseEnrollment
+            {
+                CourseSelectionOfferingId = offering.Id,
+                StudentId = student.Id
+            });
+            await db.SaveChangesAsync();
+        }
+    }
+
+    private async Task SeedDevelopmentGradesAsync()
+    {
+        if (await db.GradeSheets.AnyAsync()) return;
         var task = await db.TeachingTasks.SingleAsync(
             x => x.TaskNumber == "2026-1-CS101-01");
-        var now = DateTime.UtcNow;
-        db.CourseSelectionRounds.Add(new CourseSelectionRound
+        var student = await db.Students.SingleAsync(
+            x => x.StudentNumber == "202601001");
+        db.GradeSheets.Add(new GradeSheet
         {
-            AcademicTermId = term.Id,
-            Name = "2026—2027 学年第一学期第一轮选课",
-            StartsAt = now.AddDays(-2),
-            EndsAt = now.AddDays(14),
-            WithdrawalEndsAt = now.AddDays(21),
-            MaxCredits = 30,
-            Status = CourseSelectionRoundStatus.Open,
-            Notes = "本地开发演示轮次，可用于验证选课、退课和教学班名单。",
-            Offerings =
+            TeachingTaskId = task.Id,
+            RegularWeight = 30,
+            MidtermWeight = 0,
+            FinalWeight = 70,
+            Status = GradeSheetStatus.Draft,
+            Records =
             [
-                new CourseSelectionOffering
+                new GradeRecord
                 {
-                    TeachingTaskId = task.Id,
-                    Capacity = 60,
-                    IsOpenToAll = false,
-                    Notes = "面向计科 2026-1 班开放。"
+                    StudentId = student.Id,
+                    RegularScore = 88,
+                    FinalScore = 92,
+                    TotalScore = 90.8m,
+                    GradePoint = 4.0m
                 }
             ]
         });