Repoint the web UI footer link to git.haxx.space/sjg/trx-rs, swap the
GitHub octocat mark for a host-neutral git-branch icon, and relabel to
"trx-rs source".
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>