Generated change-log pages + footer Site link

Details

A complete /changelog/ section rendered in the v3 design language and
generated from git history at build time (output is git-ignored, never
committed):
- Overview: current version, release/feature counts, the three design
  eras, and a year grid. Then one page per year (its months), per month
  (its days), per day (its releases), and per commit — 819 pages for
  647 commits — each release showing its retroactive semantic version,
  a super-short keyword title, type badge, details, files changed and
  prev/next navigation.
- New `changelog` layout reuses the full v3 chrome (canvas backgrounds,
  nav, dock, footer); nav anchors gain an optional home prefix so
  subpages link back to the home sections.
- "Change log" link added under the footer's Site column.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Mn7fa3Z4bpbSAj4edBnjXA

Files changed (6)