Release 2026.7.3

Add - toolbar icon state, value popup, and optional on-page overlay

• The toolbar icon reflects fastmon activity per tab, no DevTools needed:
  grayed out on pages with no fastmon beacons, full-color where a beacon fired,
  reset on navigation. Uses the collector beacons the in-page tap already
  relays, so no new permissions.
• Clicking the icon opens an overview popup of the current page: Core Web
  Vitals (LCP and CLS always shown, INP/FCP/TTFB when present, rated by the
  web.dev thresholds), CDN/origin cache status derived from Server-Timing, the
  Server-Timing phase durations, and a link to app.fastmon.eu. It reads a small
  per-tab summary the service worker keeps, so it works even while the DevTools
  panel is draining beacons.
• Optional on-page overlay (off by default, toggled from the popup): a flat
  bottom-right chip showing TTFB / LCP / CLS plus CDN/origin cache status, live.
  INP is omitted because it only finalises late (on hidden/navigate).
• Cache-status colors: HIT green, MISS red, BYPASS purple, EXPIRED/STALE
  amber.

Fix

• Swallow the async "No tab with id" rejection from chrome.action.setIcon /
  setTitle when a tab closes between the triggering event and the icon update.