Add stateless MCP server to API

[mbklein]

This PR adds an MCP server at /api/v2/mcp. Testing it is a little tricky but doable on your local machine (not remote dev environment).

1. cd mcp && npm ci
2. Make sure your .bash_profile properly initializes mise or asdf or whatever local package manager you use. (It is not sufficient that .zprofile or .zshrc does it, since the MCP server launches under bash and not zsh.)
3. Make sure you have nodejs v24.11.1 installed using the aforementioned package manager.
4. Make sure Claude Desktop is not running.
5. Edit ~/Library/Application Support/Claude/claude_desktop_config.json. Create it if it doesn't exist.
6. Add the following:

   {
     "mcpServers": {
       "dc-api": {
         "command": "/path/to/dc-api-v2/mcp/bin/run.sh",
         "environment": {
           "SEARCH_MODEL_ID": "PROD_OPENSEARCH_MODEL_ID"
         }
       }
     }
   }

   You can get the prod opensearch model ID out of the production/infrastructure/index secret in AWS.

You can now launch Claude and ask about content from Digital Collections. Expand the tool calls to see requests and responses. Go to Settings > Connectors > dc-api > Configure to see a list of tools and permissions.

[kdid]

@mbklein - I'm confused about your testing instructions. Am I supposed to edit this file first?

[mbklein]

Whoops, nice catch. I'll update that.

[bmquinn]

Looks great, and I think we should handle any issues that surfaced like the erroring pagination in search results upstream from the MCP server implementation.