VS Code extension showing environment of current file

[brillout]

Description

A neat thing of the file suffixes .server.js and .client.js is that they communicate in which environment the file is loaded.

But .server.js and .client.js are meant for asserting the environment; they aren't supposed to be used for every file.

It would be neat to have an IDE extension (e.g. for VS Code) that displays some kind of visual clue communicating to the user the environment of the current file.

We can start easy by showing the environment only for + files (Vike always knows the environment of + files). This alone would be very beneficial. AFAICT it should be relatively straightforward to implement.

Later, we can see if/how we can show the environment for each user file. It has to be seen whether we can quickly crawl the user's entire dependency tree (e.g. using esbuild + es-module-lexer) but, in principle, it should be possible as proven by TypeScript's IntelliSense.