Add Waterfall Chart & Request Inspector

Features Added:
- Interactive waterfall timeline visualization
- Color-coded timing bars (DNS, Connect, SSL, TTFB, Download)
- Request filtering by resource type (HTML, JS, CSS, Images, Fonts)
- Detailed request inspector dialog with timing breakdown
- HAR data extraction from Lighthouse results
- Size/compression metrics display
- Third-party resource identification
- Render-blocking resource detection

Technical Implementation:
- Created lib/har-parser.js for network data extraction
- Built waterfall.html with SVG-based timeline renderer
- Added waterfall.js with interactive controls
- Integrated HAR generation into test runner workflow
- Updated main UI with View Waterfall link

test-db.js

@@ -0,0 +1,18 @@
+const db = require('./lib/db');
+
+(async () => {
+  console.log('Testing DB connectivity...');
+  try {
+    const client = await db.pool.connect();
+    console.log('Successfully connected to PostgreSQL!');
+    client.release();
+    
+    console.log('Initializing Schema...');
+    await db.initSchema();
+    console.log('Schema Check Complete.');
+  } catch (err) {
+    console.error('DB Connection Failed:', err);
+  } finally {
+    process.exit();
+  }
+})();