Draft: Add user tool discovery

[screenfluent]

Draft proposal for user-level tools.

I’d like to make it possible to keep personal tools while still updating mi from upstream. This explores ~/.agents/tools/*.mjs, mirroring the existing user-level skills directory.

This draft:

• loads bundled tools/*.mjs plus user ~/.agents/tools/*.mjs
• keeps the same { name, description, parameters, handler } contract
• preserves hot-loading before each model call
• prevents user tools from overriding bundled tool names
• skips broken or malformed user tools with a warning
• keeps npm run lines at 30 total

Main question: does this direction and path feel right for mi, or would you prefer a different shape?

Checks:

• npm test
• npm run lines

[av]

This is a great idea, I wanted to implement something like this too, sorry, I've only noticed the PR now, but I've actually added a global config dir, that'll be the place where the tools go