Replaces the mascot with the sketched portrait screenshot, center-cropped
to square and masked to a circle with anti-aliased edges so the PNG itself
is rounded (not just CSS). Regenerates logo.png (256), apple-touch-icon
(180), and favicon-32 at the new proportions. Adds .DS_Store to gitignore.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Bundles the artifacto mascot as /static/logo.png (256×256),
/static/favicon-32.png and /static/apple-touch-icon.png. Header
shows the logo as a small rounded avatar; browser tabs get the
favicon. Replaces the .keep placeholder.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
