feat(web): migrate course adjustment workflow

src/Jiaowu.Api/Controllers/CourseAdjustmentsController.cs

@@ -170,6 +170,25 @@ public sealed class CourseAdjustmentsController(
         return Ok(new { Task = task, Sessions = sessions, Classrooms = classrooms, Periods = periods });
     }
 
+    [HttpGet("teacher-options")]
+    [Authorize(Roles = Applicants)]
+    public async Task<ActionResult> GetTeacherOptions(CancellationToken cancellationToken)
+    {
+        return Ok(await db.Teachers.AsNoTracking()
+            .Where(x => x.Status == TeacherStatus.Active && !x.IsArchived)
+            .OrderBy(x => x.College!.Name)
+            .ThenBy(x => x.TeacherNumber)
+            .Select(x => new
+            {
+                x.Id,
+                x.TeacherNumber,
+                x.Name,
+                x.Title,
+                CollegeName = x.College!.Name
+            })
+            .ToListAsync(cancellationToken));
+    }
+
     // ═══════════════ My adjustments ═══════════════
 
     [HttpGet("mine")]
@@ -611,7 +630,8 @@ public sealed class CourseAdjustmentsController(
                     return ValidationProblem("请选择代课教师。");
                 if (!await db.Teachers.AnyAsync(x =>
                         x.Id == request.SubstituteTeacherId &&
-                        x.Status == TeacherStatus.Active, cancellationToken))
+                        x.Status == TeacherStatus.Active &&
+                        !x.IsArchived, cancellationToken))
                     return ValidationProblem("代课教师不存在或已离职。");
                 break;
             case CourseAdjustmentType.Cancel: