[Chams99]

Closes #1248

Adds isEnv() as an alias of forEnv(), so boolean expressions like not(isEnv(production)) read more naturally. Same arguments and behavior as forEnv().

Includes a test, a note on the forEnv() docs page, and the VS Code autocomplete entry.

[pullfrog]

✅ No new issues found.

Reviewed changes Reviewed the runtime alias, regression coverage, documentation, and VS Code integration. The Varlock build, 189 unit tests, and extension grammar and snapshot checks passed.

• Runtime alias: Registers isEnv() using the existing forEnv() definition, preserving argument validation, boolean inference, and environment matching.
• Regression coverage: Tests nonmatching and multiple-environment conditions, plus the requested not(isEnv(...)) expression.
• Editor and documentation: Adds resolver and boolean decorator completions, documents the alias, and includes release entries for both affected packages.

  ^{｜ View workflow run ｜ Using gpt-6.1-sol ｜ 𝕏}

[theoephraim]

I'm torn... isEnv reads slightly better in some cases, but I'm not sure forEnv is really that bad?
Not sure if it's worth having 2 ways to do it.

[Chams99]

Yeah it's a small one. Where it helps is the negated case. not(isEnv(production)) reads more like an actual condition than not(forEnv(production)). If you'd rather keep a single way to do it no worries and I can close it.

[theoephraim]

Thanks again for the PR, but yeah I think for the sake of simplicity, gonna just keep it as is.