Enhance map functionality and API documentation

- Updated API documentation for the `rebuildZooms` endpoint to clarify its long execution time and response behavior.
- Modified MapView component to manage tile cache invalidation after rebuilding zoom levels, ensuring fresh tile display.
- Introduced a new composable for handling tile cache invalidation state after admin actions.
- Enhanced character icon creation to reflect ownership status with distinct colors.
- Improved loading state handling in various components for better user experience during data fetching.

frontend-nuxt/lib/LeafletCustomTypes.ts

@@ -11,10 +11,10 @@ export interface GridCoordLayerOptions extends L.GridLayerOptions {
 
 /**
  * Grid layer that draws one coordinate label per Leaflet tile in the top-left corner.
- * coords.(x,y,z) are Leaflet tile indices and zoom; they map to game tiles as:
- *   scaleFactor = 2^(HnHMaxZoom - coords.z),
- *   topLeft = (coords.x * scaleFactor, coords.y * scaleFactor).
- * This matches backend tile URL {mapid}/{z}/{x}_{y}.png (storageZ: z=6→0, Coord = tile index).
+ * Uses only coords.z (do not use map.getZoom()) so labels stay in sync with tiles.
+ * SmartTileLayer has zoomReverse: true, so URL z = 6 - coords.z; backend maps z=6 → storageZ=0.
+ * Game tile for this Leaflet tile: scaleFactor = 2^(HnHMaxZoom - coords.z),
+ * topLeft = (coords.x * scaleFactor, coords.y * scaleFactor) — same (x,y) as backend tile.
  */
 export const GridCoordLayer = L.GridLayer.extend({
   options: {