commits: text UI buttons + Tangled feed via /api/commits
Replace all piece-specific keyboard shortcuts with ui.TextButtons
(tangled link, compact/detail, play/pause, refresh) matching the rest
of AC. Fetch from a new /api/commits endpoint that runs git log on the
Tangled remote instead of hitting GitHub's API directly, and fix the
author truncation so "prompt.ac/@jeffrey" renders as "@jeffrey".
Also label netlify.toml as deprecated — lith is the host now.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>