Previously _github_pr_url() only returned a URL when prs.github_pr was
populated. That field is set on only 3 of 4094 merged PRs (the rare cases
mirrored to the public GitHub repo), so pr_url was null for ~100% of the
feed. The frontend whole-row PR overlay (livingip-web PR #30) renders
only when pr_url is non-null, so until now no rows had the overlay.
Pipeline-attributed events (reweave/*, ingestion/*) are the most visible
victim: their /contributors/pipeline link lands on a sparse stub, with
no way to reach the actual commit/PR they refer to.
Fix: rename _github_pr_url -> _pr_url and fall back to the canonical
Forgejo URL (git.livingip.xyz/teleo/teleo-codex/pulls/{number}) when no
GitHub mirror exists. Verified 200 OK against a sample (#10568). GitHub
URL still wins when available.
Result: 1972/1972 events in _build_events now carry a pr_url. Whole-row
overlay starts working for everything including pipeline events.
e78308862a