fix(e2e): address CTO review feedback on PR #101

- Fix route mismatch: mock /api/impersonation/sessions/session-1 (plural)
- Navigate to /?sessionId=session-1 so CustomerPortal fetches session
- Replace .bg-amber-500 with data-testid="impersonation-banner"
- Remove waitForTimeout(1100), use proper waitFor
- Fix locale-dependent time regex in "banner shows started time" test
- Fix loading state race by waiting for response before fulfilling
- Add data-testid to ImpersonationBanner component
- Add trailing newlines to both spec files

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/src/portal/ImpersonationBanner.tsx

@@ -35,7 +35,7 @@ export function ImpersonationBanner({ session, isExtended, onEnd, onExtend, onSh
   }, [session.expiresAt, onEnd]);
 
   return (
-    <div className="sticky top-0 z-40 bg-amber-500 text-amber-950 px-4 py-2.5 flex flex-wrap items-center gap-x-4 gap-y-1 text-sm font-medium shadow-md">
+    <div data-testid="impersonation-banner" className="sticky top-0 z-40 bg-amber-500 text-amber-950 px-4 py-2.5 flex flex-wrap items-center gap-x-4 gap-y-1 text-sm font-medium shadow-md">
       <span className="flex items-center gap-1.5">
         <Eye size={16} />
         STAFF VIEW