Replace stretched hero portrait with compact headshot

[sabujcb]

Problem

The portrait still resolves as a tall intrinsic image in the deployed theme, stretching the hero and showing the face as a narrow vertical crop.

Changes

• add a dedicated square headshot frame that establishes its own dimensions
• take the image out of document flow inside that frame so intrinsic dimensions cannot enlarge the hero
• crop around the head and shoulders with object-fit: cover and a balanced focal position
• use a restrained 224–272 px desktop width and a compact responsive mobile width
• retain the existing high-resolution portrait and accessible alt text

Validation

• npm run lint:prettier
• git diff --check
• portfolio audit: 0 errors, 0 warnings
• academic palette contrast checks passed

Build note

Bundler is unavailable locally, so the GitHub Pages workflow must pass before merge.

Rollback

Revert the two focused branch commits.