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/characterColors.ts

@@ -0,0 +1,48 @@
+/**
+ * Palette of distinguishable colors for character markers (readable on typical map tiles).
+ * Same character id always maps to the same color via id % palette.length.
+ */
+const CHARACTER_PALETTE_FILL: string[] = [
+  '#0d9488', // teal
+  '#dc2626', // red
+  '#2563eb', // blue
+  '#16a34a', // green
+  '#ea580c', // orange
+  '#7c3aed', // violet
+  '#db2777', // pink
+  '#ca8a04', // yellow/amber
+  '#0891b2', // cyan
+  '#65a30d', // lime
+  '#4f46e5', // indigo
+  '#b45309', // brown/amber-dark
+]
+
+/** Darken a hex color by a factor (0–1). Used for stroke. */
+function darkenHex(hex: string, factor: number): string {
+  const n = hex.slice(1)
+  const r = Math.max(0, parseInt(n.slice(0, 2), 16) * (1 - factor))
+  const g = Math.max(0, parseInt(n.slice(2, 4), 16) * (1 - factor))
+  const b = Math.max(0, parseInt(n.slice(4, 6), 16) * (1 - factor))
+  return '#' + [r, g, b].map((x) => Math.round(x).toString(16).padStart(2, '0')).join('')
+}
+
+export interface CharacterColors {
+  fill: string
+  stroke: string
+}
+
+/**
+ * Returns stable fill and stroke colors for a character by id.
+ * Optionally use a distinct style for "owned by me" (e.g. brighter stroke).
+ */
+export function getColorForCharacterId(
+  id: number,
+  options?: { ownedByMe?: boolean }
+): CharacterColors {
+  const fill = CHARACTER_PALETTE_FILL[Math.abs(id) % CHARACTER_PALETTE_FILL.length]
+  const stroke = darkenHex(fill, 0.25)
+  if (options?.ownedByMe) {
+    return { fill, stroke: '#1e293b' }
+  }
+  return { fill, stroke }
+}