fix: zsh/debian/.zshrc manually-managed PATH entries hardcode /home/stanfish/ instead of $HOME

[stanfish06]

Resolved by PR #105 (merged 2026-06-08). All five manually-managed hardcoded /home/stanfish/ paths have been replaced with $HOME.

One remaining item from the original "bonus note": line 165 still hardcodes node/26.2.0 — tracked separately in a new issue.