Fix reinstall loop when tool has both binaryPath and desiredBinaryName

[albertodebortoli]

Pull Request Title

Fix reinstall loop when tool has both binaryPath and desiredBinaryName

Description

• Root cause: isToolInstalled checked binaryPath before desiredBinaryName. After first install, the archive binary is renamed to desiredBinaryName on disk, so binaryPath no longer exists. On subsequent runs isToolInstalled returned false, triggered a full re-download, re-extracted the archive, then failed with "item with the same name already exists" when trying to rename again.
• Secondary fix: reinstall now also checks desiredBinaryName before binaryPath when resolving the on-disk binary, making the intent explicit and consistent with the install path.
• No related issue.

Type of Change

• Feature
• Bug fix
• Maintenance / Refactor
• Documentation
• CI / Tooling
• Other (specify)

How Has This Been Tested?

• Added / updated unit tests
• Manually tested locally (describe)
• Tested on macOS (arch: arm64)
• Other

Two new regression tests:

• InstallerTests/test_reinstall_withDesiredBinaryName_doesNotRedownload — installs a tool twice and asserts the downloader is called exactly once (second run takes the reinstall path, not re-download).
• ToolInstallerTests/test_reinstall_withDesiredBinaryName_usesDesiredNameForSymlink — calls reinstall on a tool whose binary is stored under desiredBinaryName and verifies the symlink is created correctly.

swift test   # 375 tests, 0 failures

Checklist

• Swift code builds locally (swift build)
• Tests pass locally (swift test)
• Code style / formatting respected
• Documentation updated (README / comments)
• Version / tag alignment considered (if release related)
• PR title follows conventional style (optional)

CI Considerations

• Affects build time notably
• Requires new secrets / env vars
• Alters release process

Breaking Changes?

• No
• Yes (describe impact and migration path)

Additional Notes

Reproducer (Lucafile entry that triggered the bug):

- name: Phrase
  binaryPath: phrase_macosx_arm64
  desiredBinaryName: phrase
  version: 2.59.0
  url: https://github.com/phrase/phrase-cli/releases/download/2.59.0/phrase_macosx_arm64.zip
  ignoreArchCheck: true

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!