feat(core-audit): createAuditErasureHook Payload afterDelete factory

Adds createAuditErasureHook in core-audit/src/hooks/. The factory returns
a CollectionAfterDeleteHook that calls auditLog.eraseSubject() when a
document is deleted. Defaults to "pseudonymize" mode; coerces numeric ids
to string; skips undefined/null/object ids. Barrel at hooks/index.ts.
6 unit tests cover all guard branches.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/core-audit/src/hooks/audit-erasure-hook.test.ts

@@ -0,0 +1,65 @@
+import { describe, it, expect, vi } from "vitest";
+import { createAuditErasureHook } from "./audit-erasure-hook";
+import type { IAuditLog } from "../audit-log.interface";
+
+function makeAuditLog(): IAuditLog {
+  return {
+    record: vi.fn().mockResolvedValue(undefined),
+    eraseSubject: vi.fn().mockResolvedValue(undefined),
+  };
+}
+
+/** Minimal CollectionAfterDeleteHook args shape (only `doc` matters here). */
+function hookArgs(id: unknown) {
+  return {
+    doc: { id },
+    req: {} as never,
+    id: String(id),
+    collection: {} as never,
+    context: {},
+  };
+}
+
+describe("createAuditErasureHook", () => {
+  it("defaults to 'pseudonymize' mode", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog });
+    await hook(hookArgs("user_1") as never);
+    expect(auditLog.eraseSubject).toHaveBeenCalledWith("user_1", "pseudonymize");
+  });
+
+  it("respects explicit mode='delete'", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog, mode: "delete" });
+    await hook(hookArgs("user_2") as never);
+    expect(auditLog.eraseSubject).toHaveBeenCalledWith("user_2", "delete");
+  });
+
+  it("coerces numeric id to string", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog });
+    await hook(hookArgs(42) as never);
+    expect(auditLog.eraseSubject).toHaveBeenCalledWith("42", "pseudonymize");
+  });
+
+  it("skips when doc.id is undefined", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog });
+    await hook(hookArgs(undefined) as never);
+    expect(auditLog.eraseSubject).not.toHaveBeenCalled();
+  });
+
+  it("skips when doc.id is null", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog });
+    await hook(hookArgs(null) as never);
+    expect(auditLog.eraseSubject).not.toHaveBeenCalled();
+  });
+
+  it("skips when doc.id is an object", async () => {
+    const auditLog = makeAuditLog();
+    const hook = createAuditErasureHook({ auditLog });
+    await hook(hookArgs({ nested: true }) as never);
+    expect(auditLog.eraseSubject).not.toHaveBeenCalled();
+  });
+});