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/server/server.js

@@ -2,6 +2,11 @@ import express from 'express';
 import { WebSocketServer } from 'ws';
 import cors from 'cors';
 import { createServer } from 'http';
+import {
+  loadFullState, saveFullState, recordItemHistory,
+  saveItems, saveFurnaces, saveAlerts, saveState,
+  getHistory, closeDb,
+} from './db.js';
 
 const app = express();
 const PORT = process.env.PORT || 3001;
@@ -14,29 +19,26 @@ app.use(express.json({ limit: '5mb' }));
 const webClients = new Set();
 const bridgeClients = new Set();
 
-// Latest inventory state from the CC:Tweaked bridge
-let inventoryState = {
-  itemList: [],
-  grandTotal: 0,
-  chestCount: 0,
-  totalSlots: 0,
-  usedSlots: 0,
-  freeSlots: 0,
-  usedRatio: 0,
-  dropperOk: false,
-  barrelOk: false,
-  furnaceCount: 0,
-  furnaceStatus: {},
-};
+// Load persisted state from SQLite on startup
+console.log('💾 Loading persisted state from database...');
+const persisted = loadFullState();
 
-let activityState = {};
-let alertsState = [];
-let smeltingPaused = false;
-let disabledRecipes = {};
-let smeltableRecipes = {};
-let craftableRecipes = [];
-let craftTurtleOk = false;
-let lastUpdate = 0;
+let inventoryState = persisted.inventoryState;
+let activityState = persisted.activityState;
+let alertsState = persisted.alertsState;
+let smeltingPaused = persisted.smeltingPaused;
+let disabledRecipes = persisted.disabledRecipes;
+let smeltableRecipes = persisted.smeltableRecipes;
+let craftableRecipes = persisted.craftableRecipes;
+let craftTurtleOk = persisted.craftTurtleOk;
+let lastUpdate = persisted.lastUpdate;
+
+if (lastUpdate > 0) {
+  const ago = Math.round((Date.now() - lastUpdate) / 1000);
+  console.log(`💾 Restored state from ${ago}s ago (${inventoryState.itemList.length} items)`);
+} else {
+  console.log('💾 No previous state found, starting fresh');
+}
 
 // Pending commands for bridge HTTP polling (fallback)
 let pendingCommands = [];
@@ -109,6 +111,13 @@ app.get('/api/alerts', (req, res) => {
   res.json({ alerts: alertsState });
 });
 
+// Get item count history
+app.get('/api/history/:itemName', (req, res) => {
+  const limit = parseInt(req.query.limit) || 100;
+  const history = getHistory(req.params.itemName, Math.min(limit, 1000));
+  res.json({ item: req.params.itemName, history });
+});
+
 // Get recipes (smeltable + craftable)
 app.get('/api/recipes', (req, res) => {
   res.json({
@@ -368,7 +377,27 @@ function updateStateFromBridge(data) {
   if (data.craftTurtleOk !== undefined) craftTurtleOk = data.craftTurtleOk;
   
   lastUpdate = Date.now();
-  
+
+  // Persist to SQLite
+  try {
+    saveFullState({
+      inventoryState,
+      activityState,
+      alertsState,
+      smeltingPaused,
+      disabledRecipes,
+      smeltableRecipes,
+      craftableRecipes,
+      craftTurtleOk,
+    });
+    // Record history snapshot (throttled to every 5 min internally)
+    if (inventoryState.itemList?.length) {
+      recordItemHistory(inventoryState.itemList);
+    }
+  } catch (err) {
+    console.error('❌ DB save error:', err.message);
+  }
+
   // Broadcast to all web clients
   broadcastToClients({
     type: 'state_update',
@@ -490,7 +519,16 @@ server.listen(PORT, HOST, () => {
 });
 
 // Graceful shutdown
-process.on('SIGINT', () => {
+function shutdown() {
   console.log('\n🛑 Shutting down server...');
+  try {
+    closeDb();
+    console.log('💾 Database closed');
+  } catch (err) {
+    console.error('❌ Error closing database:', err.message);
+  }
   process.exit(0);
-});
+}
+
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);