When the operator misses a QR and retries /pair for the same label, the
previous pairing flow (Baileys session in memory + Telegram message id +
event listener) was still alive. Multiple listeners then raced to edit
the same QR message, surfacing as 400 'message is not modified' errors.
Fixes:
- Track one listener per account; new /pair tears down the previous one
- Stop the existing Baileys session and wipe its session dir so the new
attempt starts from a clean slate
- Skip duplicate QR pushes (Baileys can re-emit identical QR strings)
- Fall back to a fresh photo if editMessageMedia fails for any reason
Two pairing-flow fixes after live test:
- Connection Failure during pairing: Baileys announced a stale WhatsApp Web
version that the server rejected before the QR was emitted. Pull the
current version via fetchLatestBaileysVersion() at session start.
- Telegram mobile auto-converts straight quotes to curly quotes, so labels
like /pair "test 1" arrived as “test 1” and the curly quotes were never
stripped. Extend the quote-stripping regex on /pair, /unpair, /groups.
