fix(cli): make env shims use the active vp executable

[leohara]

Summary

Fix Unix env shims created by vp env setup so they point to the active vp executable instead of always assuming the standalone VP_HOME/current/bin/vp layout.

This keeps the existing standalone behavior when the active executable is VP_HOME/current/bin/vp, while making Homebrew-style installs work when vp lives outside VP_HOME.

Fixes #1572 .

Details

• Resolve the Unix shim target from the currently running vp
• Preserve ../current/bin/vp for standalone installs
• Recreate stale or broken Unix core shim symlinks without requiring --refresh.
• Add a global snap test that simulates an external/Homebrew-style vp and verifies:
  • shims point to the external vp
  • command -v node resolves to the Vite+ shim
  • node -v uses the project Node version

Note

This PR intentionally keeps the scope focused on vp env setup core shims. I noticed that package binary shims created by vp install -g also use the ../current/bin/vp Unix target today, but I left that out to keep this PR focused on the reported Homebrew node shim issue. If you’d prefer fixing those package shims in the same PR, I’m happy to add that follow-up change here.

Verification

• cargo test -p vite_global_cli shim -- --nocapture
• pnpm bootstrap-cli
• pnpm -C packages/cli snap-test-global command-env-setup-external-vp
• vp check --fix
• cargo clippy -p vite_global_cli --all-targets
• cargo fmt --check
• git diff --check

[netlify]

✅ Deploy Preview for viteplus-preview canceled.

Name	Link
🔨 Latest commit	f4b525c
🔍 Latest deploy log	https://app.netlify.com/projects/viteplus-preview/deploys/6a0c664311e7de0008fbc004