Greptile Summary

This PR fixes a regression where mise would use a lowercase path key on Unix (e.g., from zsh's special path array being exported), causing PATH manipulation to break. The fix splits path_key_from_env by platform: on Unix it unconditionally returns "PATH", and on Windows it keeps the existing case-insensitive lookup with a fallback.

• Unix path key hardened: PATH_KEY is now always "PATH" on Unix, regardless of what the environment contains, preventing the zsh path-vs-PATH mismatch.
• Windows behavior preserved: Case-insensitive matching via eq_ignore_ascii_case is retained, matching the Windows convention that env var names are case-insensitive.
• Tests added: Both platforms have dedicated unit tests covering the new code paths, including the lowercase-input regression case on Unix.

Confidence Score: 5/5

Targeted, well-tested fix with no risk to existing behaviour on either platform.

The change is narrow: a two-branch platform split replaces a single fragile heuristic. The Unix branch ignores its input by design, the Windows branch is functionally identical to the original. Both paths are covered by new unit tests that directly exercise the regression scenario.

No files require special attention.

Important Files Changed

_{Reviews (3): Last reviewed commit: "Merge branch 'main' into fix/zsh-path-ke..." | Re-trigger Greptile}