feat: add four new student modules (rotation, skill-video, exam-prep, academic) with backend APIs and frontend pages; add exam-prep question history with DB persistence

src/common/errors/errors.spec.ts

@@ -0,0 +1,60 @@
+import {
+  AuthorizationError,
+  ErrorKind,
+  GenerationError,
+  SystemError,
+  ValidationError,
+} from './index';
+
+describe('错误基类与分类', () => {
+  it('ValidationError 归类为 VALIDATION 且 missingFields 列出缺失字段', () => {
+    const e = ValidationError.missingFields(['type', 'title']);
+    expect(e.kind).toBe(ErrorKind.Validation);
+    expect(e.code).toBe('VALIDATION.MISSING_FIELDS');
+    expect(e.details?.missingFields).toEqual(['type', 'title']);
+  });
+
+  it('ValidationError.invalidFields 列出无效字段', () => {
+    const e = ValidationError.invalidFields(['occurredAt']);
+    expect(e.kind).toBe(ErrorKind.Validation);
+    expect(e.details?.invalidFields).toEqual(['occurredAt']);
+  });
+
+  it('GenerationError 区分失败/超时/信息不足', () => {
+    expect(GenerationError.failed().kind).toBe(ErrorKind.Generation);
+    expect(GenerationError.timedOut(30000).details?.limitMs).toBe(30000);
+    const insufficient = GenerationError.insufficientContent(['正文内容']);
+    expect(insufficient.details?.missingCategories).toEqual(['正文内容']);
+  });
+
+  it('AuthorizationError 归类为 AUTHORIZATION', () => {
+    expect(AuthorizationError.accessDenied('profile').kind).toBe(
+      ErrorKind.Authorization,
+    );
+    expect(AuthorizationError.missingConsent('research').details?.purpose).toBe(
+      'research',
+    );
+  });
+
+  it('SystemError 归类为 SYSTEM', () => {
+    expect(SystemError.internal().kind).toBe(ErrorKind.System);
+    expect(
+      SystemError.dependencyUnavailable('PubMed').details?.dependency,
+    ).toBe('PubMed');
+  });
+
+  it('toJSON 输出包含 kind/code/message/details', () => {
+    const json = ValidationError.missingFields(['title']).toJSON();
+    expect(json).toEqual({
+      kind: ErrorKind.Validation,
+      code: 'VALIDATION.MISSING_FIELDS',
+      message: expect.any(String),
+      details: { missingFields: ['title'] },
+    });
+  });
+
+  it('details 为不可变（冻结）副本', () => {
+    const e = ValidationError.missingFields(['a']);
+    expect(Object.isFrozen(e.details)).toBe(true);
+  });
+});