Implement comprehensive academic workflow updates

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

@@ -1,4 +1,5 @@
 using Jiaowu.Api.Domain.Common;
+using Jiaowu.Api.Domain.Identity;
 
 namespace Jiaowu.Api.Domain.Academic;
 
@@ -32,6 +33,35 @@ public sealed class WarningRecord : EntityBase
     public DateTime? AcknowledgedAt { get; set; }
     public string? AcknowledgeComment { get; set; }
     public Guid AcademicTermId { get; set; }
+    public AcademicRiskCase? RiskCase { get; set; }
+}
+
+/// <summary>Confidential follow-up work created for an academic warning.</summary>
+public sealed class AcademicRiskCase : EntityBase
+{
+    public Guid WarningRecordId { get; set; }
+    public WarningRecord? WarningRecord { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public Guid AssignedCounselorUserId { get; set; }
+    public ApplicationUser? AssignedCounselorUser { get; set; }
+    public AcademicRiskCaseStatus Status { get; set; } = AcademicRiskCaseStatus.PendingFollowUp;
+    public DateOnly FollowUpDueDate { get; set; }
+    public DateOnly? ReviewDate { get; set; }
+    public DateTime? TaskCompletedAt { get; set; }
+    public List<AcademicRiskCaseEntry> Entries { get; set; } = [];
+}
+
+/// <summary>Confidential counseling or support entry. Never exposed to students or unassigned staff.</summary>
+public sealed class AcademicRiskCaseEntry : EntityBase
+{
+    public Guid AcademicRiskCaseId { get; set; }
+    public AcademicRiskCase? AcademicRiskCase { get; set; }
+    public AcademicRiskEntryType Type { get; set; }
+    public required string Content { get; set; }
+    public DateTime OccurredAt { get; set; }
+    public Guid RecordedByUserId { get; set; }
+    public ApplicationUser? RecordedByUser { get; set; }
 }
 
 public enum WarningType
@@ -49,3 +79,6 @@ public enum WarningStatus
     Resolved = 3,
     Dismissed = 4
 }
+
+public enum AcademicRiskCaseStatus { PendingFollowUp = 1, InProgress = 2, PendingReview = 3, Closed = 4 }
+public enum AcademicRiskEntryType { Counseling = 1, SupportMeasure = 2, Review = 3 }