feat(voice): add reusable geometry actions

- turn named places and mapped landmarks into reusable bounded areas
- count loaded records inside resolved, drawn and annotated geometry
- find recent imagery for an area, the view or the pointer snapshot
- keep osm place search behind an operator-configured overpass endpoint
- preserve cancellation, ownership and follow-up memory across every action
- cover geometry, provider lifecycle, cache isolation and voice routing

.env.example

@@ -192,6 +192,7 @@ AISSTREAM_API_KEY=
 # CCTV_FORCE_AUSTIN=                                   # force live default sources when a source-pack JSON is configured
 
 # Optional: comma-separated Overpass URLs; use only instances you run or pay for.
+# Also enables voice place search (osm_query, "hospitals in Kathmandu").
 OVERPASS_UPSTREAMS=
 
 # Optional: place-lookup endpoints. Lookups try bundled data first, then the