chore: improve accessibility baseline checks

[CoderDeltaLAN]

Improves baseline accessibility without changing the visual design.

Scope:

• add explicit labels for contact form fields;
• add touch/coarse-pointer fallback for the custom cursor;
• add verify.sh checks to preserve the accessibility baseline;
• keep GSAP loading unchanged to avoid breaking runtime behavior without visual testing.

Constraints:

• README.md untouched;
• no backend;
• no secrets;
• no generated/vendor artifacts.

Local validation:

• scripts/verify.sh OK;
• git diff --check OK;
• accessibility postcheck OK;
• pre-push validation OK.