Daily cron at 12:00 UTC (plus manual dispatch) that:
1. Fetches from the Sulkta-Coop/element-x-upstream pull-mirror
2. Fast-forwards main to upstream/develop if it has advanced
3. Measures how many commits behind main the wallet branch is now
4. Posts a ping to the Infra Matrix room so we know a rebase is due
Uses the house-bot (Matrix) account for notifications; token lives in
the repo's MATRIX_HOUSE_BOT_TOKEN Actions secret.
Removed .github/workflows/* — upstream's 18 workflows are GitHub-specific
(GITHUB_TOKEN scopes, Firebase / Sonar / Sentry / Localazy secrets we
don't have, macOS runners, etc). They were triggering on every push and
failing immediately, flooding the runner log. We're not proposing these
back upstream — we're a fork that doesn't publish to Play/F-Droid, so
their CI isn't ours to run.
If we ever need to see upstream's workflow definitions for reference,
they're one click away on github.com/element-hq/element-x-android.