feat(auth): wire instrumentation — users repo spans + sign-in/up/out withSpan

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

packages/auth/src/infrastructure/repositories/users.repository.span.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from "vitest";
+import { RecordingTracer, RecordingLogger } from "@repo/core-testing/instrumentation";
+import { MockUsersRepository } from "@/infrastructure/repositories/users.repository.mock";
+
+// Mock repo also wraps in spans (R42); easier to assert without booting Payload.
+describe("MockUsersRepository emits spans (R42)", () => {
+  it("getUser emits one span with op='repository'", async () => {
+    const tracer = new RecordingTracer();
+    const logger = new RecordingLogger();
+    const repo = new MockUsersRepository([], tracer, logger);
+    await repo.getUser("missing");
+    expect(tracer.spans).toHaveLength(1);
+    expect(tracer.spans[0]).toMatchObject({
+      name: "users.getUser",
+      op: "repository",
+    });
+    expect(tracer.spans[0]!.attributes.id).toBe("missing");
+    expect(tracer.spans[0]!.attributes.found).toBe(false);
+  });
+
+  it("getUserByUsername emits a span with emailDomain attribute", async () => {
+    const tracer = new RecordingTracer();
+    const repo = new MockUsersRepository(
+      [{ id: "1", username: "alice", passwordHash: "hash" }],
+      tracer,
+    );
+    await repo.getUserByUsername("alice");
+    expect(tracer.findSpan("users.getUserByUsername")).toBeDefined();
+    expect(tracer.findSpan("users.getUserByUsername")!.attributes.found).toBe(true);
+  });
+
+  it("createUser records created=true", async () => {
+    const tracer = new RecordingTracer();
+    const repo = new MockUsersRepository([], tracer);
+    await repo.createUser({ id: "u1", username: "charlie", passwordHash: "hash" });
+    expect(tracer.findSpan("users.createUser")).toBeDefined();
+    expect(tracer.findSpan("users.createUser")!.attributes.created).toBe(true);
+  });
+});