feat(navi): GPS origin + place detail panel + basic actions

Adds synthetic "Your location" stop A when GPS granted; place
detail panel slides in on search result click with Directions /
Add stop / Save (stub) / Share actions; elevation via Valhalla
/height; react-hot-toast for feedback; pendingDestination state
for GPS-denied Directions flow.

Phase 3 Step 5 C1 of Navi.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -13,11 +13,13 @@
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
     "@dnd-kit/utilities": "^3.2.2",
+    "lucide-react": "^1.8.0",
     "maplibre-gl": "^5.23.0",
     "pmtiles": "^4.4.1",
     "protomaps-themes-base": "^4.5.0",
     "react": "^19.2.5",
     "react-dom": "^19.2.5",
+    "react-hot-toast": "^2.6.0",
     "zustand": "^5.0.12"
   },
   "devDependencies": {