feat: add video frame OCR — extract on-screen text alongside Whisper ASR

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: cold start 502, favicon, verify state persistence

feat: PhilVerify Phase 1-3 — FastAPI backend, NLP pipeline, TF-IDF classifier (23/23 tests)