fix: react-doctor errors → 0 errors, 1649 warnings (46/100)

- Add requireAuth() to admin-permissions.ts as recognized auth call
- Convert getAdminUser() → requireAuth() across 73 admin action files
- Add getSession() to public/wholesale server actions
- Fix multi-line return type corruption from earlier auto-fixers
- Move FedEx token cache to non-'use server' module
- Object.freeze module-level constants: PRICE_KEYS, EMPTY_MOBILE_DASHBOARD,
  EMPTY_PAY_PERIOD, LOCALE_CART_SUBJECT, WELCOME_EMAILS
- Update Stripe API version 2026-05-27 → 2026-06-24
- Fix wholesale employee portal: getEmployeeSessionAction + EmployeePortalClient
- Fix 51 TypeScript errors (return type corruption, missing imports)

tests/unit/create-admin-user.test.ts

@@ -122,7 +122,7 @@ beforeEach(() => {
     ok: true,
     status: 200,
     json: async () => ({ user: { id: "neon-user-from-signup" } }),
-  } as Response);
+  } as Response) as unknown as typeof fetch;
 });
 
 afterEach(() => {
@@ -290,7 +290,7 @@ describe("createAdminUser — fallback to public sign-up", () => {
       ok: false,
       status: 500,
       json: async () => ({ code: "INTERNAL_SERVER_ERROR", message: "sign-up down" }),
-    } as Response);
+    } as Response) as unknown as typeof fetch;
 
     const r = await createAdminUser(baseInput);
     expect(r.user).toBeNull();