* mcp: support sse
Didn't seem like Claude Desktop configs have SSE support yet, but I did
the obvious of having an object with a `url`. I also added a `type`
(optional for stdio) so we can better disambiguate types of configs.
Example .vscode/mcp.json:
```
{
"servers": {
"everything": {
"type": "sse",
"url": "http://localhost:3001/sse"
}
}
}
```
Closes#243242
* update layer check
Adds new eslint rule which requires `export` be used for public api types
The `export` is not actually needed, but our existing typing files largely use it. This makes it consistent
Pedantic but we mostly use `Array<x | y>` for arrays of unions instead of `(x | y)[]`. Just adding an eslint rule and updating some places to be consistent
