Implement Model Context Protocol server poc (#552)

<!--

Make sure you've read the CONTRIBUTING.md guidelines:
https://github.com/stack-auth/stack-auth/blob/dev/CONTRIBUTING.md

-->

<!-- ELLIPSIS_HIDDEN -->


----

> [!IMPORTANT]
> Introduces a new Model Context Protocol server with OpenAPI
integration, updates build configurations, and adds necessary files for
initial release.
> 
>   - **New MCP Server**:
> - Implements MCP server in `src/index.ts` using
`@modelcontextprotocol/sdk`.
> - Handles tool requests with `ListToolsRequestSchema` and
`CallToolRequestSchema`.
>     - Supports 40 endpoints, defined in `operationIDs`.
>   - **OpenAPI Integration**:
> - Generates OpenAPI schema in `generate-openapi.ts` and writes to
`mcp-server/openapi`.
> - Converts OpenAPI parameters to JSON schema in
`openapi-to-jsonschema.ts`.
>   - **Configuration and Build**:
> - Adds `package.json` for MCP server with dependencies and scripts.
>     - Configures ESLint in `.eslintrc.cjs`.
> - Updates `Dockerfile` and `turbo.json` to include MCP server in build
process.
>   - **Miscellaneous**:
>     - Adds `.gitignore` for OpenAPI JSON files.
>     - Initial release noted in `CHANGELOG.md`.
> 
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=stack-auth%2Fstack-auth&utm_source=github&utm_medium=referral)<sup>
for d0970c4059. It will automatically
update as commits are pushed.</sup>


<!-- ELLIPSIS_HIDDEN -->

---------

Co-authored-by: Konsti Wohlwend <[email protected]>

docker/server/Dockerfile

@@ -26,7 +26,7 @@ COPY . .
 RUN tsx ./scripts/generate-sdks.ts
 
 # https://turbo.build/repo/docs/guides/tools/docker
-RUN turbo prune --scope=@stackframe/stack-backend --scope=@stackframe/stack-dashboard --docker
+RUN turbo prune --scope=@stackframe/stack-backend --scope=@stackframe/stack-dashboard --scope=@stackframe/mcp-server --docker
 
 
 # Build stage