docs: rewrite portfolio to reflect current work focus

Restructured categories around formal verification, neurosymbolic AI,
and original languages. Added arcvix papers callout and feedback
welcome notice. Replaced deleted polystack with boj-server. Added
proven, echidna, panll, typed-wasm, verisimdb, IDApTIK, ephapax,
and other key projects missing from the old version.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath