点名、成绩册统一读取“行政班在籍学生 ∪ 已选课学生”，不再错误显示 0 人。

教师选课名单改为展示全部本人教学班及完整学生名单，支持 Excel 导出。
调停课改用教师专用教学班接口，并在服务端限制只能操作本人教学班。

src/Jiaowu.Api/Controllers/AttendanceController.cs

@@ -7,6 +7,7 @@ using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -48,9 +49,15 @@ public sealed class AttendanceController(
                 TermName = x.AcademicTerm!.Name,
                 CourseCode = x.Course!.Code,
                 CourseName = x.Course!.Name,
-                StudentCount = db.CourseEnrollments.Count(enrollment =>
-                    enrollment.Status == CourseEnrollmentStatus.Enrolled &&
-                    enrollment.CourseSelectionOffering!.TeachingTaskId == x.Id),
+                StudentCount = db.Students.Count(student =>
+                    (student.Status == StudentStatus.Active &&
+                     x.Classes.Any(assignment =>
+                         assignment.AdministrativeClassId ==
+                         student.AdministrativeClassId)) ||
+                    db.CourseEnrollments.Any(enrollment =>
+                        enrollment.StudentId == student.Id &&
+                        enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                        enrollment.CourseSelectionOffering!.TeachingTaskId == x.Id)),
                 SheetCount = db.AttendanceSheets.Count(sheet =>
                     sheet.TeachingTaskId == x.Id)
             })
@@ -104,15 +111,13 @@ public sealed class AttendanceController(
             .FirstOrDefaultAsync(x => x.Id == request.TeachingTaskId, cancellationToken);
         if (task is null) return NotFound();
 
-        var studentIds = await db.CourseEnrollments.AsNoTracking()
-            .Where(x =>
-                x.Status == CourseEnrollmentStatus.Enrolled &&
-                x.CourseSelectionOffering!.TeachingTaskId == request.TeachingTaskId)
-            .Select(x => x.StudentId)
-            .Distinct()
+        var studentIds = await TeachingTaskRosterQuery
+            .ForTask(db, request.TeachingTaskId)
+            .AsNoTracking()
+            .Select(x => x.Id)
             .ToListAsync(cancellationToken);
         if (studentIds.Count == 0)
-            return ConflictProblem("该教学班没有有效选课学生。");
+            return ConflictProblem("该教学班没有有效学生。");
 
         var checkInMethod = request.CheckInMethod ?? AttendanceCheckInMethod.Manual;
         if (!Enum.IsDefined(checkInMethod))
@@ -1032,16 +1037,14 @@ public sealed class AttendanceController(
             .FirstOrDefaultAsync(cancellationToken);
         if (course is null) return null;
 
-        var enrolledStudents = await db.CourseEnrollments.AsNoTracking()
-            .Where(x =>
-                x.Status == CourseEnrollmentStatus.Enrolled &&
-                x.CourseSelectionOffering!.TeachingTaskId == teachingTaskId)
+        var enrolledStudents = await TeachingTaskRosterQuery
+            .ForTask(db, teachingTaskId)
+            .AsNoTracking()
             .Select(x => new AttendanceStatisticsStudentIdentity(
-                x.StudentId,
-                x.Student!.StudentNumber,
-                x.Student.Name,
-                x.Student.AdministrativeClass!.Name))
-            .Distinct()
+                x.Id,
+                x.StudentNumber,
+                x.Name,
+                x.AdministrativeClass!.Name))
             .ToListAsync(cancellationToken);
 
         var submittedSheets = await db.AttendanceSheets.AsNoTracking()