- Add platform detection to prepareMcpConfig() via detectPlatform()
- Skip GitHub public MCP server (ghcr.io/github/github-mcp-server) on Forgejo
- Skip checkActionsReadPermission on Forgejo (workflow token has full access)
- Reuse existing github-actions-server.ts for both platforms (no duplication)
- Add 6 Forgejo-specific tests to install-mcp-server.test.ts
- Updated PRD checkboxes for M6
Progress: 67% complete (6/9 milestones) - M7 now unblocked
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>