Full Typescript conversion as well as support for output schemas for tool calls

[dparish]

You work on this is fantastic. It made a complicated problem very easy. I liked it so much I wanted to contribute.

There are quite a few changes here.

1. I converted the repo to full typescript
2. I pulled in the mcp schema typescript to make it easier to do things like add structuredContent
3. Added support for an output schema and for annotations to tool calls
4. Converted to a more modern build system
5. Converted the tests to vitest

Some things that would be nice to do next

1. Fix the linter and formatter. They don't appear to work (either before or after my conversion).
2. Remove the authorization code. I think that would be better served with authorization lambda's
3. Remove the extraneous example zod schemas
4. Find a way to support Zod 3 and Zod 4

Sorry for the size of the diff. I used git mv to change the files from .mjs to .ts but that got stripped out somehow.

BTW you can complete get rid of all of this if you like. No hard feelings if you don't want to keep it. I'm going to borrow some of your concepts and create a version of this that fits well with middy.