feat: trend filter, engagement metrics, duplicate protection, watermark consistency

feat: HF keep-alive, IG token reminder, auto hashtags, budget alerts, hashtag suggestions

fix: set statement_timeout at connection level + add 60s migration budget

fix: set 30s statement_timeout per migration to override Supabase default

fix: remove vector ALTER TABLE from migrations (columns exist, causing timeouts)

fix: run each migration in its own transaction to survive statement timeouts

fix: make column migrations non-fatal so server starts even on timeout

fix: add DB connection timeout to prevent hanging on Neon cold start

fix: reset stuck generating posts on startup after server crash

Initial deployment to HF Spaces