This is a substantial rewrite of how the extension decides whether a site is
blocked.

Previous versions concluded a site was blocked whenever a request failed. That
cannot tell real censorship apart from a domain that no longer exists, a hotel
or airport wifi login page, or your own ad blocker — so a lot of what earlier
versions reported was not censorship at all.

Version 3 reads the actual server response and checks an independent public DNS
resolver before reporting anything:

• A site nobody anywhere can resolve is recorded as a dead domain, not as
censorship
• A "checking your browser" bot page is recorded as reachable, because the
connection worked
• Anything the extension cannot be confident about is discarded rather than
reported

Also in this release:

• Tests are split into small batches so results are no longer lost when the
browser suspends background work
• Site permissions are now an explicit list of exactly what is tested, instead
of broad wildcards
• Runs on Firefox for Android
• Fixes a registration failure that prevented the extension from connecting to
the measurement network

No browsing data is collected. The extension reports only the outcome of its own
scheduled tests.

Rewritten detection engine.

Previous versions decided a site was blocked whenever a request failed. That
could not distinguish real interference from a domain that no longer exists, a
captive portal, or a local content blocker.

This version reads real HTTP responses and checks an independent public DNS
resolver before reporting anything. A domain that nobody can resolve is now
reported as a dead domain rather than as censorship, and a bot-check page is
reported as reachable rather than blocked.

Also in this release:
- Test cycles are split into small batches so results are no longer lost when
the browser suspends the background script.
- Host permissions are now an explicit list of the sites being tested, instead
of broad wildcards.
- Runs on Firefox for Android.

No browsing data is collected. The extension reports only the outcome of its own
scheduled tests.

v1.0.1 - Bug fixes and Chrome Web Store compliance

• Fixed: Background service worker now loads correctly
• Fixed: Storage permission properly utilized
• Improved: Cross-browser compatibility (Firefox + Chrome)
• No user-facing changes - extension works exactly as before