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

src/voice/sessionCommands.js

@@ -89,7 +89,7 @@ export function createVoiceCommands({
       pointer?.clear();
       referents?.clear();
       // Conversation memory ("those", "the last answer") ends with the
-      // session.
+      // session; area handles live for the page.
       runner.resetConversation?.();
     }
   });