fix: don't add args or env to mcp.json file if args or env is empty

[chungjac]

Problem

• if a user does not include args or env fields when adding mcp server, it will be empty in the mcp.json
• user can input environment variable with a name but no value, and also a value but no name

Solution

• do not add args or env fields in mcp.json if fields are empty
• field validation for env variables: must have both name and value, or neither

Screen.Recording.2025-05-27.at.6.08.50.PM.mov

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.