fix startup of webclient through cli

[cliffhall]

In cli/src/cli.ts

• start the web client via client/bin/start.js rather than client/bin/client.js
• remove the environment related stuff from that launch because client/bin/start.js will read the env and do the right thing

Motivation and Context

If started from the default entry point of the npm package cli/build/cli.js, the proxy token isn't being created and passed to the client on the query string.

So in our local development environment, when we ran npm run start or npm run dev we were getting an appropriate startup. However when starting from the command line with npx -y @modelcontextprotocol/inspector@latest we were invoking cli/src/cli.ts which in turn invoked client/bin/client.js if you weren't asking for the cli version of the inspector.

How Has This Been Tested?

By invoking with the npm package entry point cli/src/cli.ts.

Without any extra environment vars

With extra environment vars

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

The issue arose with refactoring done in #529 and #555

[felixweinberger]

Tested with a local check out via node cli/build/cli.js

I think the PORT: CLIENT_PORT is unnecessary though

[felixweinberger]

Changing point about PORT: CLIENT_PORT to a nit

[felixweinberger]

Thank you!