- Replace manual community token entry with OAuth button that redirects
to VK authorization and auto-saves token via /vk/callback
- Fix groups.get API call (was groups.getById) to correctly retrieve
admin group id and name from user token response
- Fix price comparison: VK price.amount is in roubles, not kopecks
- Keep manual token input as fallback when VK_CLIENT_ID is not set
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
