Add Instagram social post link

Finalize submission: tags, demo video, social post, team (eldinosaur + Fred1e4), PyME/SAT framing

Bump Gradio 6.15.2 -> 6.18.0 (6.15.2 hangs on loading spinner / tabs unresponsive; 6.18.0 verified working in browser)

English-default UI + bilingual agent + USA tax support (Schedule C/SE/federal) and expanded US+EN regulation corpus

PocketAccountant: custom ledger UI + deterministic agent (engine, ledger, retrieval, classifier)

initial commit