Support for multiple/parallel specs

Thanks for building this!

Currently, the `spec.md` file is global and is written to the root folder of the project (https://github.com/addyosmani/agent-skills/blob/main/.claude/commands/spec.md), which is probably ok if you are working on a single task/spec at a time, but I was wondering if the flow can be improved so that specs/tasks/todos are scoped to a particular `/spec` command as opposed to a global `spec.md` file?

I believe OpenSpec, Spec Kit, etc. have this level of scoping already which is useful.

Thanks