Footer now compares the running SOURCE_COMMIT against origin/main via
Gitea's compare API and renders "build <sha> (latest)" when up to date
or "build <sha> (N behind)" otherwise — so it's obvious from any page
whether the deploy is current.
Per-SHA cache (60s TTL, 1.5s timeout) keeps the lookup off the hot path
in steady state. Network or parse errors return None and the parens
suffix is just hidden — the SHA itself always renders, so a flaky git
host can never break the layout.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
