feat: Consolidated UX improvements for map selection

- Snap selection to feature geometry when clicking labeled places
- Add wikidata enrichment for basemap labels (population, description)
- Differentiate visual feedback: reticle marker vs pulsing highlight
- Clear previous feature highlight when selection changes
- Store selection mode (reticle/feature) and feature info in state

Frontend: MapView click handler, PlaceDetail wikidata fetch, CSS
Backend: /api/place/wikidata/<id> route for Wikidata API lookups

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.css

@@ -279,6 +279,20 @@ body {
   background: var(--accent);
   pointer-events: none;
 }
+.navi-feature-highlight {
+  position: relative;
+  width: 24px;
+  height: 24px;
+  border-radius: 50%;
+  border: 2px solid var(--accent);
+  background: var(--accent-muted);
+  animation: navi-pulse 1.5s ease-in-out infinite;
+  pointer-events: none;
+}
+@keyframes navi-pulse {
+  0%, 100% { transform: scale(1); opacity: 0.8; }
+  50% { transform: scale(1.2); opacity: 0.5; }
+}
 
 /* ═══ PLACE DETAIL PANEL ═══ */
 .navi-place-detail {