Support installing custom modes (sometimes called primary agents) in agents that support them. - **opencode**: https://opencode.ai/docs/agents/#primary-agents - **Copilot**: https://code.visualstudio.com/docs/copilot/customization/custom-chat-modes#_custom-chat-modes - **Claude Code**: https://docs.anthropic.com/en/docs/claude-code/output-styles - **Cursor**: https://docs.cursor.com/en/agent/modes#custom