fix(block2): sharing config UX + discovery + labels (raw feedback batch)

From on-device feedback:
- Area is no longer shown as a raw geohash 'name'. 'Use my location' is the
  primary action; a human status line says whether your area is set (coarse,
  never exact). The geohash code + the relay servers moved under 'Advanced'
  (code field labelled 'a code like sp3e9 — not a place name'), which also
  brings back node/relay selection that had been fully hidden.
- Location denial no longer yanks you into system settings — returns quietly
  with an actionable inline message.
- Discovery no longer spins forever when nobody's sharing nearby: a timeout
  resolves 'searching' to the empty state.
- Home card 'Open market' -> 'Market' + 'Discover and share seeds nearby'
  (the word 'open' confused).

i18n en/es/pt; analyzer clean; the use-my-location test asserts the status flip.

apps/app_seeds/lib/state/offers_cubit.dart

@@ -76,6 +76,7 @@ class OffersCubit extends Cubit<OffersState> {
   /// (null in tests, where the transport is a fake with nothing to close).
   final Future<void> Function()? _onDispose;
   StreamSubscription<Offer>? _sub;
+  Timer? _searchTimeout;
 
   /// Whether a live transport is available (relay configured and reachable).
   bool get isOnline => _transport != null;
@@ -88,6 +89,7 @@ class OffersCubit extends Cubit<OffersState> {
       return;
     }
     await _sub?.cancel();
+    _searchTimeout?.cancel();
     emit(OffersState(
       areaGeohash: geohashPrefix,
       searching: true,
@@ -99,6 +101,14 @@ class OffersCubit extends Cubit<OffersState> {
       onError: (Object e) =>
           emit(state.copyWith(searching: false, error: () => '$e')),
     );
+    // The discover stream stays open for live offers and never signals "done",
+    // so stop the spinner after a beat: no results → show the empty state, not
+    // an endless "searching".
+    _searchTimeout = Timer(const Duration(seconds: 6), () {
+      if (!isClosed && state.searching) {
+        emit(state.copyWith(searching: false));
+      }
+    });
   }
 
   /// Publishes [offer]; returns the transport's verdict. No-op result when
@@ -157,6 +167,7 @@ class OffersCubit extends Cubit<OffersState> {
 
   @override
   Future<void> close() async {
+    _searchTimeout?.cancel();
     await _sub?.cancel();
     await _onDispose?.call();
     return super.close();