feat(core-edu): 完整实现 core-edu 教学核心服务

包含 classes/exams/homework/grades/attendance/scheduling 域、outbox、iam-consumer、redis 配置等完整实现

services/core-edu/src/exams/exam-state-machine.ts

@@ -0,0 +1,60 @@
+/**
+ * 考试状态机（纯函数）
+ *
+ * 状态流转（ISSUE-003 仲裁 scheme A）：
+ *   draft → published → in_progress → grading → graded → archived
+ *                                                    └→ cancelled（终态）
+ *   cancelled 可从 published/in_progress/grading 流入（异常终止）
+ *
+ * archived 为软删除终态（ISSUE-006 决策 #7：archived 仅做软删除，不物理删除）
+ */
+export type ExamStatus =
+  | "draft"
+  | "published"
+  | "in_progress"
+  | "grading"
+  | "graded"
+  | "archived"
+  | "cancelled";
+
+export type ExamAction =
+  "publish" | "start" | "submit" | "grade" | "archive" | "cancel";
+
+const TRANSITIONS: Record<
+  ExamStatus,
+  Partial<Record<ExamAction, ExamStatus>>
+> = {
+  draft: { publish: "published", cancel: "cancelled" },
+  published: { start: "in_progress", cancel: "cancelled" },
+  in_progress: { submit: "grading", cancel: "cancelled" },
+  grading: { grade: "graded", cancel: "cancelled" },
+  graded: { archive: "archived" },
+  archived: {},
+  cancelled: {},
+};
+
+export function canTransition(from: ExamStatus, action: ExamAction): boolean {
+  return TRANSITIONS[from]?.[action] !== undefined;
+}
+
+export function transition(from: ExamStatus, action: ExamAction): ExamStatus {
+  const next = TRANSITIONS[from]?.[action];
+  if (!next) {
+    throw new Error(`Invalid exam state transition: ${from} --${action}-->`);
+  }
+  return next;
+}
+
+export function isTerminal(status: ExamStatus): boolean {
+  return status === "archived" || status === "cancelled";
+}
+
+export const EXAM_STATUSES: readonly ExamStatus[] = [
+  "draft",
+  "published",
+  "in_progress",
+  "grading",
+  "graded",
+  "archived",
+  "cancelled",
+] as const;