Show notification on long env load

Some environments, especially Nix ones take a lot of time to load when are not cached. That means blocking everything until they load, without any info to user.

A status bar would be helpful. Since first load should always be synchronous, add a timeout to it. If it times out (configurable timeout), show "Takes too long to load" message, and start loading it in background, updating status bar/notification/debugging window with latest console messages.

The issue names no files, tests, or entry points. Start by locating the environment-loading flow and existing status bar or notification handling, then trace the first-load path. Done means a configurable timeout, a clear long-load message, background continuation, and updated progress or debug output.

Written by the indexing model from the issue text.