security(audit): log owner-bypass reads in GET /pets/:id/profile-summary (GRO-2062)

Adds a defense-in-depth audit row to impersonationAuditLogs when the
staff-side owner-bypass path fires. Mirrors the failure-isolation
pattern in src/middleware/portalAudit.ts: insert failures are logged
and swallowed so a working read can never turn into a 500.

- New writeOwnerBypassAudit helper called only when isOwner === true.
- No DB migration; petId + actorStaffId go inside metadata jsonb.
- resolveImpersonationClientId stays pure (no audit side effects).
- Positive + negative tests + a cross-tenant regression test.
- UAT_PLAYBOOK.md §3.19d: TC-API-3.19d documents the audit assertion.

Parent tracking: GRO-2062 (Paperclip).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/__tests__/petProfileSummary.test.ts

@@ -182,6 +182,11 @@ let selectQueue: Array<{
   throw?: string;
 }> = [];
 
+// Captured `db.insert(table).values(vals)` calls. Mirrors the pattern from
+// src/__tests__/impersonation.test.ts so the GRO-2063 audit row assertions
+// can inspect what the route tried to write without needing a real DB.
+let insertCapture: Array<{ table: string; vals: Record<string, unknown> }> = [];
+
 function enqueue(table: string, rows: unknown[] = []) {
   selectQueue.push({ table, rows });
 }
@@ -196,6 +201,7 @@ function resetMock() {
   servicesTable = [makeService()];
   sessionsTable = [makeSession()];
   selectQueue = [];
+  insertCapture = [];
 }
 
 // ─── Module mocks ───────────────────────────────────────────────────────────
@@ -269,7 +275,12 @@ vi.mock("@groombook/db", () => {
       select: (_cols?: Record<string, unknown>) => ({
         from: (table: { _name?: string }) => wrapRows(takeQueuedRows(table._name ?? "")),
       }),
-      insert: () => ({ values: () => ({ returning: () => [{}] }) }),
+      insert: (table: { _name?: string }) => ({
+        values: (vals: Record<string, unknown>) => {
+          insertCapture.push({ table: table._name ?? "unknown", vals });
+          return { returning: () => [{}] };
+        },
+      }),
       update: () => ({ set: () => ({ where: () => ({ returning: () => [{}] }) }) }),
       delete: () => ({ where: () => ({ returning: () => [{}] }) }),
     }),
@@ -278,6 +289,7 @@ vi.mock("@groombook/db", () => {
     staff: makeTable("staff"),
     services: makeTable("services"),
     impersonationSessions: makeTable("impersonationSessions"),
+    impersonationAuditLogs: makeTable("impersonation_audit_logs"),
     and: vi.fn((..._args: unknown[]) => ({})),
     desc: vi.fn((c: unknown) => c),
     eq: vi.fn((_a: unknown, _b: unknown) => ({})),
@@ -567,3 +579,69 @@ describe("GET /:id/profile-summary — owner-bypass (GRO-2013)", () => {
     expect(res.status).toBe(403);
   });
 });
+
+// ─── GRO-2063 owner-bypass audit write ──────────────────────────────────────
+
+describe("GET /:id/profile-summary — owner-bypass audit row (GRO-2063)", () => {
+  it("writes exactly one audit row on the owner-bypass success path", async () => {
+    enqueue("pets", petsTable);
+    enqueue("impersonationSessions", sessionsTable); // valid active session for CLIENT_ID
+    enqueue("appointments", appointmentsTable);
+    enqueue("appointments", [{ count: 1 }]);
+    enqueue("appointments", []);
+
+    const app = buildApp(CUSTOMER_STAFF);
+    const res = await app.request(`/pets/${PET_ID}/profile-summary`, {
+      headers: { "X-Impersonation-Session-Id": "sess-owner" },
+    });
+    expect(res.status).toBe(200);
+
+    const auditInserts = insertCapture.filter((c) => c.table === "impersonation_audit_logs");
+    expect(auditInserts).toHaveLength(1);
+    const vals = auditInserts[0]!.vals;
+    expect(vals.action).toBe("read_profile_summary");
+    expect(vals.sessionId).toBe("sess-owner");
+    expect(vals.pageVisited).toBe(`/pets/${PET_ID}/profile-summary`);
+    expect(vals.metadata).toEqual({
+      petId: PET_ID,
+      actorStaffId: CUSTOMER_STAFF.id,
+    });
+  });
+
+  it("does NOT write an audit row on the normal groomer-linkage success path", async () => {
+    // GROOMER is a "real" groomer with appointment linkage, NOT the
+    // auto-provisioned customer-as-groomer. No impersonation header is
+    // present, so the owner-bypass branch never executes.
+    enqueue("pets", petsTable);
+    enqueue("appointments", [{ id: "appt-1" }]); // linkage found
+    enqueue("appointments", appointmentsTable);
+    enqueue("appointments", [{ count: 1 }]);
+    enqueue("appointments", []);
+
+    const app = buildApp(GROOMER);
+    const res = await app.request(`/pets/${PET_ID}/profile-summary`);
+    expect(res.status).toBe(200);
+
+    const auditInserts = insertCapture.filter((c) => c.table === "impersonation_audit_logs");
+    expect(auditInserts).toHaveLength(0);
+  });
+
+  it("does NOT write an audit row when the owner-bypass attempt is denied (cross-tenant)", async () => {
+    // Customer has a valid session but it points at a different client.
+    // isOwner=false, falls through to groomer linkage check, returns 403.
+    enqueue("pets", [
+      makePet({ id: OTHER_CLIENT_PET_ID, clientId: "c0000002-0000-0000-0000-000000000002" }),
+    ]);
+    enqueue("impersonationSessions", sessionsTable); // session is for CLIENT_ID
+    enqueue("appointments", []); // no linkage → 403
+
+    const app = buildApp(CUSTOMER_STAFF);
+    const res = await app.request(`/pets/${OTHER_CLIENT_PET_ID}/profile-summary`, {
+      headers: { "X-Impersonation-Session-Id": "sess-owner" },
+    });
+    expect(res.status).toBe(403);
+
+    const auditInserts = insertCapture.filter((c) => c.table === "impersonation_audit_logs");
+    expect(auditInserts).toHaveLength(0);
+  });
+});