Add Docker support and fix rating change extraction

- Add Dockerfile with optimized Puppeteer configuration for containers
- Add .dockerignore for efficient builds
- Fix rating change regex to match actual PDGA format (no brackets)
- Update Puppeteer launch args for Docker compatibility
- Use new headless mode to resolve deprecation warning

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

server.js

@@ -20,7 +20,18 @@ async function scrapePDGARating(pdgaNumber) {
     return cached.data;
   }
   
-  const browser = await puppeteer.launch({ headless: true });
+  const browser = await puppeteer.launch({ 
+    headless: "new",
+    args: [
+      '--no-sandbox',
+      '--disable-setuid-sandbox',
+      '--disable-dev-shm-usage',
+      '--disable-accelerated-2d-canvas',
+      '--no-first-run',
+      '--no-zygote',
+      '--disable-gpu'
+    ]
+  });
   const page = await browser.newPage();
   
   try {
@@ -37,29 +48,14 @@ async function scrapePDGARating(pdgaNumber) {
       for (const el of elements) {
         const text = el.innerText || el.textContent;
         if (text.includes('Current Rating:')) {
-          console.log('Found rating text:', text);
           const ratingMatch = text.match(/Current Rating:\s*(\d+)/);
           
-          // Try different patterns for rating change
-          const changePatterns = [
-            /\[(\+\d+)\]/,
-            /\[(\-\d+)\]/,
-            /(\+\d+)/,
-            /(\-\d+)/
-          ];
-          
-          let change = null;
-          for (const pattern of changePatterns) {
-            const match = text.match(pattern);
-            if (match) {
-              change = match[1];
-              break;
-            }
-          }
+          // Look for rating change pattern: "Current Rating: 911 +6 (as of..."
+          const changeMatch = text.match(/Current Rating:\s*\d+\s+([+\-]\d+)\s+\(as of/);
           
           return {
             rating: ratingMatch ? ratingMatch[1] : null,
-            change: change
+            change: changeMatch ? changeMatch[1] : null
           };
         }
       }
@@ -318,7 +314,18 @@ app.get('/api/ratings', async (req, res) => {
 app.post('/api/predicted-rating/:pdgaNumber', async (req, res) => {
   try {
     const { pdgaNumber } = req.params;
-    const browser = await puppeteer.launch({ headless: true });
+    const browser = await puppeteer.launch({ 
+      headless: "new",
+      args: [
+        '--no-sandbox',
+        '--disable-setuid-sandbox',
+        '--disable-dev-shm-usage',
+        '--disable-accelerated-2d-canvas',
+        '--no-first-run',
+        '--no-zygote',
+        '--disable-gpu'
+      ]
+    });
     
     console.log(`Calculating predicted rating for PDGA ${pdgaNumber}...`);
     const predictedRating = await getPredictedRating(browser, pdgaNumber);