fix(GRO-1212): add missing impersonationAuditLogs mock in portal.test.ts

Add impersonationAuditLogs table mock and db.insert() method to the
@groombook/db mock in portal.test.ts to resolve "No 'impersonationAuditLogs'
export is defined" errors. The portalAudit middleware calls db.insert()
on every request, which was missing from the mock.

Passes all 26 portal tests.

apps/api/src/__tests__/portal.test.ts

@@ -72,6 +72,11 @@ vi.mock("@groombook/db", () => {
     { get: (t, p) => (p === "_name" ? "appointments" : { table: "appointments", column: p }) }
   );
 
+  const impersonationAuditLogs = new Proxy(
+    { _name: "impersonationAuditLogs" },
+    { get: (t, p) => (p === "_name" ? "impersonationAuditLogs" : { table: "impersonationAuditLogs", column: p }) }
+  );
+
   return {
     getDb: () => ({
       select: () => ({
@@ -99,9 +104,15 @@ vi.mock("@groombook/db", () => {
           }),
         }),
       }),
+      insert: () => ({
+        values: () => ({
+          returning: () => [],
+        }),
+      }),
     }),
     impersonationSessions,
     appointments,
+    impersonationAuditLogs,
     eq: vi.fn(),
     and: vi.fn(),
   };