Add cache management and smart delay optimization

- Add subtle "clear cache" link (gear icon) in top-right corner
- Implement cache clearing endpoint with user feedback
- Fix delay logic to skip delays for cached data
- Only apply rate limiting delays when actually scraping fresh data
- Add cache size reporting when clearing cache
- Improve performance for repeat visits with cached data
- Maintain server-friendly rate limiting for fresh scrapes

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

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

server.js

@@ -371,6 +371,11 @@ async function getAllRatings(progressCallback = null) {
       }
       
       try {
+        // Check if data is cached BEFORE scraping
+        const cacheKey = `player-${pdgaNumber}`;
+        const cached = cache.get(cacheKey);
+        const wasFromCache = cached && Date.now() - cached.timestamp < CACHE_DURATION;
+        
         const playerData = await scrapePDGARating(pdgaNumber);
         ratings.push(playerData);
         
@@ -384,8 +389,10 @@ async function getAllRatings(progressCallback = null) {
           });
         }
         
-        // Longer delay to avoid overwhelming the server
-        await new Promise(resolve => setTimeout(resolve, 1000));
+        if (!wasFromCache) {
+          // Delay only for fresh scrapes to avoid overwhelming the server
+          await new Promise(resolve => setTimeout(resolve, 1000));
+        }
       } catch (error) {
         console.error(`Failed to scrape PDGA ${pdgaNumber}:`, error.message);
         const errorData = {
@@ -576,6 +583,21 @@ app.get('/api/rating-history/:pdgaNumber', async (req, res) => {
   }
 });
 
+app.post('/api/clear-cache', (req, res) => {
+  try {
+    const cacheSize = cache.size;
+    cache.clear();
+    console.log(`Cache cleared - removed ${cacheSize} entries`);
+    res.json({ 
+      success: true, 
+      message: `Cache cleared - ${cacheSize} entries removed` 
+    });
+  } catch (error) {
+    console.error('Error clearing cache:', error);
+    res.status(500).json({ error: 'Failed to clear cache' });
+  }
+});
+
 app.post('/api/predicted-rating/:pdgaNumber', async (req, res) => {
   let browser = null;
   try {