* feat: add VK channel support
- Add VK channel implementation using vksdk
- Support text messages and media attachments
- Implement Long Poll API for real-time messaging
- Add group chat support with trigger prefixes
- Add user whitelist (allow_from) configuration
- Add VK channel documentation
Files:
- pkg/channels/vk/: VK channel implementation
- pkg/config/config.go: Add VKConfig structure
- pkg/channels/manager.go: Register VK channel
- pkg/gateway/gateway.go: Import VK channel package
- docs/channels/vk/: Usage documentation
* test: add unit tests for VK channel
- Test channel initialization with various configurations
- Test allow_from whitelist functionality
- Test group trigger configuration
- Test max message length (4000 chars)
- Test message splitting logic
- Test attachment processing
All tests passing ✓
* fix: resolve linting issues in VK channel
- Format VKConfig struct tags to comply with golines
- Remove unused mu sync.Mutex field
- Remove unused stripPrefix method
All tests passing ✓
* style: format VKConfig with golines
- Align struct tags to match project style
- Match formatting with other channel configs (Telegram, etc.)
- Fix golines linting error
* style: fix struct tag formatting in config.go
* docs: update VK channel docs to use secure token storage
* feat(vk): add voice capabilities support
- Implement VoiceCapabilities() method for VK channel
- Add audio_message attachment handling in processAttachments
- Add comprehensive tests for voice capabilities
- Support both ASR (speech-to-text) and TTS (text-to-speech)
* docs: add VK channel to documentation and update voice support
- Add VK channel to README.md and README.zh.md channel lists
- Update VK channel documentation with voice message support
- Document ASR and TTS capabilities for VK channel
- Add voice transcription configuration reference