Add a GPS map editor card at the top of asset details, allowing users to
manually set an asset's GPS coordinates via an interactive Leaflet map.
- GPS card with Leaflet map and draggable marker
- 🔒 Lock/unlock toggle (locked by default when GPS exists)
- 💾 Save GPS button (visible only when unlocked)
- Saves via PUT /api/assets/{id} with lat/lng
- Click on map or drag marker to set position
- Fallback to Orlando coords (28.5383, -81.3792) when no GPS
- Auto-refresh detail view after save
Closes#61
shawn
18743ffdde