fix: resolve timezone offset in VOD end_time calculations

style: optimize transcribe_confirm prompt and skip fully transcribed audio

feat: add backfill resume support and session/retry fixes for VODs

fix: date parsing format for Whisper sync

feat: global roles migration, VIP badges, role backfiller script

feat: tune Whisper settings and add word mappings

fix: adjust Whisper parameters to disable temperature fallback and prevent hallucinations on silence/noise

feat: prepare transition to decoupled hosting (Render + Netlify + Supabase)