feat: add MCP server support for user-home relative editor config paths and Windsurf editor

[arturaz]

[arturaz]

I've tested it out, MCP server is added automatically and works.

[kasiaMarek]

I'm hesitant if we should merge this. It seems that currently there is no way to enable/disable an MCP plugin in windsurf per workspace. Adding Metals MCP server globally will allow to use only a single workspace with Metals MCP at a time, leaving behind a stale/misleading configuration.

[arturaz]

Had an idea: what if we would disambiguate the metals MCP server by giving them names that are full paths to the project?

Then when updating the file we could remove stale entries by checking if the path on disk still exists.

[tgodzik]

That might work I guess 🤔