fix(bun): create bunx alongside bun.exe on Windows install

[JamBalaya56562]

Summary

mise install bun on Windows extracts bun.exe from the upstream
bun-windows-x64.zip release but does not create a bunx entry, so
bunx <pkg> is broken under mise-managed bun on Windows. The unix
releases include a bunx symlink pointing at bun, and the upstream
PowerShell installer mirrors that on Windows by calling
bun completions (oven-sh/bun:src/cli/install_completions_command.zig,
installBunxSymlinkWindows). The mise core bun plugin had no
equivalent, so package.json scripts, Playwright webServer.command,
mise tasks, etc. that invoke bunx all failed.

Reproduction (before this PR)

$ mise install bun@1.3.13
$ ls (mise where bun)/bin/
bun.exe              # bunx is missing
$ bunx --version
# command not found

What changed

• src/plugins/core/bun.rs: after extracting the Windows zip, create
  a bunx entry next to bun.exe. Try a hardlink bunx.exe -> bun.exe
  first (matches upstream — bun inspects argv[0] and switches to bunx
  mode the same way the unix symlink does), and fall back to a
  bunx.cmd shim using the literal upstream uses
  (@%~dp0bun.exe x %*) for filesystems where hardlinks fail.
• mise's reshim picks the new entry up automatically because both
  .exe and .cmd are in the default windows_executable_extensions,
  so a bunx.exe shim lands in ~/AppData/Local/mise/shims/
  with no further plumbing.
• e2e-win/bun.Tests.ps1: assert that the bun bin dir contains a
  bunx entry after install and that mise x bun -- bunx --version
  returns the expected version.

Test plan

• Manual mise install bun@1.3.13 --force on Windows 11
  produces a working bunx (verified end-to-end via the mise
  shim — bunx --version returns 1.3.13).
• cargo +stable-x86_64-pc-windows-msvc check -p mise clean
  (no new warnings).
• cargo fmt --all -- --check clean.
• CI passes on the Windows runner (the new bun.Tests.ps1).
• Linux / macOS install path unchanged — existing bunx
  symlink intact (no regression; the new code is gated behind
  #[cfg(windows)]).

References

• Upstream Windows shim creation:
  oven-sh/bun:src/cli/install_completions_command.zig
  (installBunxSymlinkWindows)
• Upstream PowerShell installer that triggers it:
  oven-sh/bun:src/cli/install.ps1

[greptile-apps]

Greptile Summary

This PR fixes the missing bunx on Windows after mise install bun by mirroring the step the upstream bun PowerShell installer performs: creating a bunx.exe hardlink (matching bun's argv[0] dispatch) or falling back to a quoted bunx.cmd shim for filesystems that don't support hardlinks.

• src/plugins/core/bun.rs: Adds install_bunx_windows, called immediately after the zip is extracted on Windows. Attempts a hardlink first; on failure logs a debug message and writes a single-line bunx.cmd with the path properly quoted to handle spaces in the install directory (improvement over upstream's unquoted form).
• e2e-win/bun.Tests.ps1: New Pester test that asserts bun.exe and at least one bunx entry exist after install and that mise x bun@1.3.13 -- bunx --version returns the installed version.

Confidence Score: 5/5

Safe to merge — the change is narrowly scoped to Windows install post-processing and is compile-time gated so it cannot regress Unix behaviour.

The new install_bunx_windows function handles both the happy path (hardlink) and a well-known fallback (cmd shim) with correct path quoting, idempotent cleanup, and informative debug logging. The Unix symlink path is completely untouched. Previous thread concerns (quoting, remove_all semantics) have been addressed in this revision.

No files require special attention.

Important Files Changed

Filename	Overview
src/plugins/core/bun.rs	Adds install_bunx_windows to create a bunx.exe hardlink (preferred) or bunx.cmd shim fallback after Windows zip extraction; correctly gated behind #[cfg(windows)] with no impact on Unix paths.
e2e-win/bun.Tests.ps1	New Pester test that verifies bun.exe and a bunx entry (either .exe or .cmd) are present after install, and that bunx --version returns the expected version string via mise x.

_{Reviews (3): Last reviewed commit: "fix(bun): create bunx alongside bun.exe ..." | Re-trigger Greptile}

[gemini-code-assist]

Code Review

This pull request adds Windows-specific support for the Bun plugin to ensure bunx is available after installation, either via a hard link or a .cmd shim, and includes a new E2E test. The review feedback recommends using the internal file module for safer file cleanup and notes that the Bun version used in the tests is likely invalid and should be updated.