Critical fixes: Cache busting + Remove throttling + Ensure correct defaults

1. Browser Cache Fix:
   - Added ?v=4.0 to main.js to force browser reload
   - This ensures new comparison/waterfall UI loads

2. Remove ALL Throttling:
   - Disabled Lighthouse network throttling (rttMs=0, throughput=0)
   - Disabled CPU throttling (cpuSlowdownMultiplier=1)
   - Set throttlingMethod to 'provided' (no simulation)
   - Applies to both mobile and desktop tests

3. Backend Default Already Fixed:
   - isMobile defaults to false (desktop) matching frontend

This fixes all 3 reported issues

lib/runner.js

@@ -100,6 +100,15 @@ async function _executeTest(url, options) {
       screenEmulation: isMobile 
         ? undefined // Uses default mobile emulation
         : { mobile: false, width: 1350, height: 940, deviceScaleFactor: 1, disabled: false },
+      throttling: {
+        rttMs: 0,
+        throughputKbps: 0,
+        cpuSlowdownMultiplier: 1,
+        requestLatencyMs: 0,
+        downloadThroughputKbps: 0,
+        uploadThroughputKbps: 0
+      },
+      throttlingMethod: 'provided'
     },
   };