Add LDA topic inference — show detected topic label + defining words in UI

Add ML model comparison panel showing BoW, TF-IDF, Naive Bayes, and LDA results

fix: remove leftover 'source' variable reference after Firebase removal

refactor: remove Firebase dependency — use REST API for history

feat: extension button placement, text extraction, OCR display + ML improvements

feat: landing page UX improvements — mock result card, crosshatch hero, teaser centering, nav home link

ux: improve landing — fix step visuals, add try-it teaser input, expand footer with nav links

feat: add landing page — hero, modes, how-it-works, stats, CTA band

feat: add clickable example suggestion chips for text and url tabs

chore: add HF Spaces deployment config and fix frontend API URL

Fix: Overhaul Facebook post detection to filtered comments using [role='feed'] strategy and improve button positioning

feat: oEmbed scraping for Facebook/X URLs, remove social URL blocks

fix(frontend): block social URL preview + better error card for social URLs

fix: cold start 502, favicon, verify state persistence

feat(frontend): apply frontend-design, web-design-guidelines, architect-review skills