feat(core-audit): StdoutJsonAuditLog impl with audit + audit-erasure markers

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

packages/core-audit/src/stdout-json-audit-log.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { StdoutJsonAuditLog } from "./stdout-json-audit-log";
+import type { AuditEntry } from "@repo/core-shared/audit";
+
+const sample: AuditEntry = {
+  actorId: "user_1",
+  actorType: "user",
+  actorRoles: ["admin"],
+  action: "CREATE",
+  resource: { type: "articles", id: "abc" },
+  at: new Date("2026-05-11T10:00:00.000Z"),
+  scope: { feature: "blog", environment: "production", tenant: "default" },
+  from: { ipTruncated: "10.0.0.0", userAgent: "Mozilla/5.0" },
+  containsPii: false,
+  outcome: "success",
+};
+
+describe("StdoutJsonAuditLog", () => {
+  let writeSpy: ReturnType<typeof vi.spyOn>;
+  beforeEach(() => {
+    writeSpy = vi.spyOn(process.stdout, "write").mockImplementation(() => true);
+  });
+
+  it("record() writes one JSON line per entry to stdout", async () => {
+    const log = new StdoutJsonAuditLog();
+    await log.record(sample);
+    expect(writeSpy).toHaveBeenCalledOnce();
+    const written = writeSpy.mock.calls[0]![0] as string;
+    expect(written.endsWith("\n")).toBe(true);
+    const parsed = JSON.parse(written.trimEnd());
+    expect(parsed._type).toBe("audit");
+    expect(parsed.actorId).toBe("user_1");
+    expect(parsed.action).toBe("CREATE");
+    expect(parsed.at).toBe("2026-05-11T10:00:00.000Z");  // ISO 8601 serialization
+  });
+
+  it("eraseSubject() emits a tombstone with mode + actorId", async () => {
+    const log = new StdoutJsonAuditLog();
+    await log.eraseSubject("user_1", "pseudonymize");
+    expect(writeSpy).toHaveBeenCalledOnce();
+    const written = writeSpy.mock.calls[0]![0] as string;
+    const parsed = JSON.parse(written.trimEnd());
+    expect(parsed._type).toBe("audit-erasure");
+    expect(parsed.actorId).toBe("user_1");
+    expect(parsed.mode).toBe("pseudonymize");
+    expect(typeof parsed.at).toBe("string");  // ISO 8601 timestamp
+  });
+});