feat: add Google Maps → Email pipeline (Tab 4)

- New Maps page with keyword + region chips, German city presets, query preview, enrichment toggle
- Google Maps Places API (New) service with pagination and deduplication
- maps-enrich job route: Maps search → store raw leads → optional Anymailfinder bulk enrichment
- Settings: Google Maps API key credential card with Places API instructions
- Sidebar: MapPin nav item + googlemaps credential status indicator
- Results: maps job type with MapPin icon (text-green-400)
- Credentials API: added googlemaps to SERVICES array and test endpoint

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

components/layout/TopBar.tsx

@@ -8,6 +8,7 @@ const BREADCRUMBS: Record<string, string> = {
   "/airscale": "AirScale → Email",
   "/linkedin": "LinkedIn → Email",
   "/serp": "SERP → Email",
+  "/maps": "Google Maps → Email",
   "/results": "Results & History",
   "/settings": "Settings",
 };