0.18.2: setup pairing start hotfix

[llblab]

Summary

This hotfix fixes first-time /telegram-setup pairing startup after the 0.18.1 transport hotfix.

It updates the live in-memory Telegram config immediately after the validated token is persisted and before polling starts, so the extension no longer prints pairing guidance while the poller still sees an unconfigured bot.

Why

In 0.18.1, setup could validate the token and show Send /start..., but startPolling() still read the old in-memory config because setConfig() happened only after runTelegramSetup() returned. On a fresh install this could produce Telegram bot is not configured, leave the status at telegram awaiting pairing, and make /start appear ignored even though the operator followed the prompt.

User-visible behavior

• First-time /telegram-setup updates live config before starting polling.
• The pairing prompt is no longer shown ahead of a poller that still thinks the bot is unconfigured.
• /start can be received after successful setup without restarting Pi.

Changed areas

• lib/setup.ts: persists and updates live config before notifying and starting polling.
• tests/setup.test.ts, tests/config.test.ts: cover the config-before-polling ordering.
• Package metadata/changelog: bumps @llblab/pi-telegram to 0.18.2.

Risk Notes

No config migration required. The change only moves live config update earlier in the existing successful setup path, after token validation and persistence succeed.

Validation

• npm run validate — passed (typecheck, tests, audit, pack dry-run)
• repo_context_check /home/llb/.pi/agent/extensions/pi-telegram — passed, 0 errors / 0 warnings