Quality improvements: Unicode chars, Token class, imports, type hints, formatting

fix: webagent at /webagent/ via lifespan mount; ticker shows real HN+BBC news

feat: easter egg CSS injected via js_on_load (no gr.Blocks css= deprecation)

fix: complete easter egg rewrite using Gradio 6 js= API

fix: CSS via gr.Blocks(css=) + serve webagent as static files

test: add comprehensive easter egg tests