Optional argument for generate-requirements command

[chilinglee]

Hi! Thank you for this excellent MCP server - it's been really helpful.

I'm using this MCP server with VS Code Github Copilot. When using /mcp.spec-driven.generate-requirements, I need to enter text in the command palette before reaching Copilot's chat interface. Currently, I type something like "Hi" just to proceed to where I can enter my actual requirements.

Would it be possible to make the argument optional, allowing going directly to Copilot without the extra step?

Thanks again for all your work on this!