Give git.progmasoft.com a phone layout

On a phone the mirror pages were drawn 980 px wide and scaled down to
unreadable text (Android Chrome, desktop mode off): head.html had no
viewport meta, so the narrow-screen rules of progmasoft-git.css never
applied.

- head.html declares width=device-width, initial-scale=1.
- Below 720 px the page keeps a 12 px margin, and lists, files, diffs
  and preformatted text scroll inside their own box instead of widening
  the page.

Deployed to the server and checked with Playwright at 390 px (index,
summary, tree, log, file, commit): body text 15 px, no page overflow.

Claude-Session: https://claude.ai/code/session_01Ji7xZMYjc4zankoc7hGBE1

0 files changed, 0 insertions, 0 deletions