fix(search): geocode through the server, not the browser

- Google's Geocoding web service refuses referrer-restricted keys, so the
  browser call forced GOOGLE_MAPS_API_KEY to ship unrestricted
- add /api/google/geocode and /api/google/reverse-geocode, using the server
  key like Places and Street View already do
- the browser key now needs the Map Tiles API only

server/providers/places/google-key.js

@@ -14,12 +14,33 @@ export function keylessGooglePlacesResponse(apiKey) {
 }
 
 /**
- * Google API key for the SERVER-SIDE calls (Places nearby/text search, the
- * CCTV Street View fallback). These never reach the browser, so this key can
- * be restricted by server IP and scoped to Places API + Street View Static
- * API — while GOOGLE_MAPS_API_KEY stays referrer-restricted to Map Tiles +
- * Geocoding for the browser (#33). Splitting them is opt-in: unset, this
- * falls back to the shared browser key and nothing changes.
+ * Geocoding speaks Google's own response shape rather than the `places: []`
+ * contract its two siblings use, because the browser adapters read `status`
+ * and `results` directly. The keyless capability reads the same way: a status
+ * that is not `OK` and no results, which the adapters already treat as "this
+ * provider did not answer" and pass to the next geocoder in the chain.
+ */
+export function keylessGoogleGeocodeResponse(apiKey) {
+  if (String(apiKey ?? '').trim()) return null;
+  return {
+    statusCode: 200,
+    payload: {
+      configured: false,
+      status: 'REQUEST_DENIED',
+      results: [],
+      error: null,
+    },
+  };
+}
+
+/**
+ * Google API key for the SERVER-SIDE calls (Places nearby/text search,
+ * geocoding, the CCTV Street View fallback). These never reach the browser, so
+ * this key can be restricted by server IP and scoped to Places API + Geocoding
+ * API + Street View Static API — while GOOGLE_MAPS_API_KEY stays
+ * referrer-restricted to Map Tiles for the browser (#33, #363). Splitting them
+ * is opt-in: unset, this falls back to the shared browser key, which then has
+ * to carry every API both sides use and cannot take a referrer restriction.
  */
 export function googleServerApiKey() {
   return resolveGoogleServerKey(process.env);