Release v0.0.20

[akatz-ai]

Summary

• Bump comfygit-manager to v0.0.20 and comfygit-core to 0.3.17
• Update documentation URLs from comfyhub.org to comfygit.org
• Fix infinite recursion in generateUUID and race condition in queue processing
• Add version bump protocol to CLAUDE.md

Test plan

• Verify panel loads and displays version 0.0.20
• Confirm environment switching and git operations work with core 0.3.17