No way to use an env variable with an empty string as a meaningful value

[vanyauhalin]

Describe the bug

Not always empty string the same as undefined. Sometimes a variable can have three states instead of two: a string value, an empty string, and an undefined value.

To Reproduce

npm exec -- mcp-inspector -e MY_ENV= -- node main.js

Expected behavior

Treat an empty string as an actual value.

Logs

Invalid parameter format: MY_ENV=. Use key=value format.

Additional context

https://github.com/modelcontextprotocol/inspector/blob/0.16.1/cli/src/cli.ts#L147-L151
https://github.com/modelcontextprotocol/inspector/blob/0.16.1/cli/src/index.ts#L171-L175