Add SQLite persistence + official Minecraft item icons

Database (better-sqlite3):
- Persist items, furnaces, alerts, recipes, settings to SQLite
- Auto-restore last known state when server restarts or bridge disconnects
- Item count history tracking (5-min snapshots, 7-day retention)
- /api/history/:itemName endpoint for item count history
- Docker volume for database file persistence
- Graceful shutdown with DB connection cleanup

Icons:
- Replace mc-heads.net with official Minecraft game textures via CDN
- Cascading fallback: item texture -> block texture -> emoji
- In-memory URL cache to avoid redundant network requests
- Block texture suffix mapping (furnace_front, barrel_top, etc.)
- Crisp pixel-art rendering with image-rendering: pixelated

web/client/src/utils/itemUtils.js

@@ -1,27 +1,17 @@
 /**
- * Minecraft item icon utility
- * Uses mc-heads.net item renders for actual Minecraft item icons
+ * Minecraft item utility functions
+ * Icons use official game textures via ItemIcon component
  */
 
 // Format an item name for display
 export function formatItemName(name) {
   if (!name) return '';
   return name
-    .replace(/^[a-z0-9_]+:/, '') // Strip mod prefix
+    .replace(/^[a-z0-9_.-]+:/, '') // Strip mod prefix
     .replace(/_/g, ' ')
     .replace(/\b\w/g, (c) => c.toUpperCase());
 }
 
-// Get icon URL for a Minecraft item
-// Uses mc-heads.net which provides 2D item renders
-export function getItemIconUrl(itemName, size = 32) {
-  if (!itemName) return null;
-  // mc-heads.net format: https://mc-heads.net/item/{item_name}
-  // Alternatively we can use crafatar or other MC icon APIs
-  // For items, we use a simple mapping approach
-  return `https://mc-heads.net/item/${itemName}/${size}`;
-}
-
 // Fallback emoji mapping for common item categories
 const CATEGORY_EMOJI = {
   ingot: '🪙',