Use remote Chromium container instead of local Puppeteer launch

- Add browserless/chromium container to docker-compose
- Add docker-compose.dev.yml for local dev (Chromium on port 3001)
- Browser scraper connects via WebSocket (CHROMIUM_WS env var)
- Falls back to local launch if CHROMIUM_WS not set
- Remove Chromium install from Dockerfile (smaller image)
- Auto-reconnect on browser disconnect

Tested: remote Chromium connects in ~500ms, HG Spot scrapes in
~2.2s total. No longer blocks the Node.js event loop.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server/config.ts

@@ -5,5 +5,6 @@ export const config = {
   host: process.env.HOST || '0.0.0.0',
   databasePath: process.env.DATABASE_PATH || './data/pricehunter.db',
   storesDir: process.env.STORES_DIR || './stores',
+  chromiumWs: process.env.CHROMIUM_WS || '',
   isProduction: process.env.NODE_ENV === 'production',
 };

src/server/scraper/browser-scraper.ts

@@ -1,6 +1,7 @@
 import type { Browser } from 'puppeteer';
 import type { Store } from '../models/store.js';
 import type { ScrapedItem } from './result-parser.js';
+import { config } from '../config.js';
 
 let browser: Browser | null = null;
 
@@ -14,20 +15,37 @@ function log(msg: string) {
 async function getBrowser(): Promise<Browser> {
   if (browser && browser.connected) return browser;
 
-  log('Launching Chromium...');
   const puppeteer = await import('puppeteer');
-  browser = await puppeteer.default.launch({
-    headless: true,
-    args: [
-      '--no-sandbox',
-      '--disable-setuid-sandbox',
-      '--disable-dev-shm-usage',
-      '--disable-gpu',
-      '--disable-extensions',
-      '--no-first-run',
-    ],
+
+  if (config.chromiumWs) {
+    // Connect to remote Chromium (Docker container)
+    log(`Connecting to remote Chromium at ${config.chromiumWs}`);
+    browser = await puppeteer.default.connect({
+      browserWSEndpoint: config.chromiumWs,
+    });
+    log('Connected to remote Chromium');
+  } else {
+    // Fall back to local launch
+    log('Launching local Chromium...');
+    browser = await puppeteer.default.launch({
+      headless: true,
+      args: [
+        '--no-sandbox',
+        '--disable-setuid-sandbox',
+        '--disable-dev-shm-usage',
+        '--disable-gpu',
+        '--disable-extensions',
+        '--no-first-run',
+      ],
+    });
+    log('Local Chromium launched');
+  }
+
+  // Reconnect if browser disconnects
+  browser.on('disconnected', () => {
+    log('Browser disconnected');
+    browser = null;
   });
-  log('Chromium launched');
 
   return browser;
 }
@@ -73,7 +91,6 @@ export async function scrapeStoreWithBrowser(store: Store, searchUrl: string): P
     }
     log(`${store.name}: selector found`);
 
-    // Brief wait for remaining renders
     await new Promise((r) => setTimeout(r, 300));
 
     log(`${store.name}: extracting products...`);
@@ -124,7 +141,11 @@ export async function warmupBrowser(): Promise<void> {
 
 export async function closeBrowser(): Promise<void> {
   if (browser) {
-    await browser.close();
+    if (config.chromiumWs) {
+      browser.disconnect();
+    } else {
+      await browser.close();
+    }
     browser = null;
   }
 }