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

SECURITY.md

@@ -20,18 +20,18 @@ The golden rule: **secret-bearing API keys stay on the server side.** The dev/pr
 | `OPENAI_API_KEY` | Server only | Browser fetches a short-lived **ephemeral** Realtime session token from `/api/realtime/token`; the real key never ships |
 | `AISSTREAM_API_KEY` | Server only | Server holds the AISStream websocket; browser polls the same-origin `/api/ais-live` cache |
 | OpenSky OAuth (`OPENSKY_CLIENT_ID/SECRET`) | Server only | Server mints + refreshes the token behind `/api/opensky` |
-| `GOOGLE_MAPS_SERVER_API_KEY` (optional, #33) | Server only | Server calls Places (`/api/google/nearby-places`, `/api/google/text-search`) and the Street View fallback with this key; falls back to `GOOGLE_MAPS_API_KEY` when unset |
+| `GOOGLE_MAPS_SERVER_API_KEY` (optional, #33) | Server only | Server calls Places (`/api/google/nearby-places`, `/api/google/text-search`), Geocoding (`/api/google/geocode`, `/api/google/reverse-geocode`) and the Street View fallback with this key; falls back to `GOOGLE_MAPS_API_KEY` when unset |
 
 ### Two deliberately client-side keys — restrict them
 
 These are designed to be used directly in the browser (like a Mapbox public token). They are injected into the client bundle via Vite's `define`, so they **will** be visible in browser devtools. Scope and restrict them rather than trying to hide them:
 
-1. **Google Maps API key** — loads Photorealistic 3D Tiles directly and powers GEV place search. **Restrict it** (HTTP referrer + API restriction to the required Google APIs) in the Google Cloud Console. An unrestricted key in a public deployment can be abused and billed to you.
+1. **Google Maps API key** — loads Photorealistic 3D Tiles directly. **Restrict it** (HTTP referrer + API restriction to the required Google APIs) in the Google Cloud Console. An unrestricted key in a public deployment can be abused and billed to you. Restrict it to the **Map Tiles API only**: a referrer restriction applies to the Maps JavaScript API and the client SDKs, not to the web services, so a key carrying Geocoding under one is refused with `API keys with referer restrictions cannot be used with this API`. Search does not need it — geocoding goes through the server proxies above (#363).
 2. **Cesium ion token** (`CESIUM_ION_TOKEN`, optional — for ion-hosted Google Photorealistic 3D Tiles, Bing world imagery, and world terrain) — used as `Cesium.Ion.defaultAccessToken` client-side. Use a public **`assets:read`** token with **URL restrictions** for any hosted deployment. The Community plan has eligibility and usage limits; a public token is not a secret, but it can still consume the account's quota.
 
 > The explicit browser `define` block in `build/vite.js` controls exactly what reaches the client: only these two keys. Everything else stays server-side.
 
-**Places and Street View never needed to be on that list** (#33): they're called from the server-side proxies in the table above, which use `GOOGLE_MAPS_SERVER_API_KEY` when it's set. Splitting it from the browser-exposed key lets each key's Google Cloud restriction actually match what it does — the browser key referrer-restricted to the APIs the client loads, the server key IP-restricted (never a referrer, since it never leaves your server) to Places + Street View Static — instead of one key that has to be either over-permissioned or broken for one of its two jobs. A single shared `GOOGLE_MAPS_API_KEY` still works if you don't split them; it just has to cover every API both sides use.
+**Places, Geocoding and Street View never needed to be on that list** (#33, #363): they're called from the server-side proxies in the table above, which use `GOOGLE_MAPS_SERVER_API_KEY` when it's set. Splitting it from the browser-exposed key lets each key's Google Cloud restriction actually match what it does — the browser key referrer-restricted to Map Tiles, the server key IP-restricted (never a referrer, since it never leaves your server) to Places + Geocoding + Street View Static — instead of one key that has to be either over-permissioned or broken for one of its jobs. A single shared `GOOGLE_MAPS_API_KEY` still works if you don't split them, but then it cannot carry a referrer restriction at all: the web services refuse one, and search would be the half that breaks.
 
 Never commit real keys. `.env` is gitignored; only `.env.example` (placeholder names) is tracked. On macOS `dev-fresh.sh` can read keys from the Keychain; plain Vite uses env vars or a local `.env`, and Pinokio uses its ignored app `ENVIRONMENT` file.