cmd/reinstall: avoid leaving .reinstall directories

[cho-m]

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One situation this happens is brew reinstall --ask where choosing "no" would result in the keg being renamed to .reinstall which can cause issues as brew only expects these to exist during an ongoing reinstall operation.

[Copilot]

Pull request overview

This PR addresses an issue where .reinstall backup directories were being left behind when brew reinstall --ask operations were cancelled. The fix refactors the restore_backup method to accept an InstallationContext parameter and adds explicit backup restoration when formulas are skipped or when exceptions occur.

Key Changes:

• Refactored restore_backup to accept InstallationContext instead of individual parameters
• Added backup restoration when formulas are excluded from valid installers (e.g., user declines with --ask)
• Added exception handler to restore all backups if any error occurs during reinstallation

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
Library/Homebrew/reinstall.rb	Refactored restore_backup method signature to use InstallationContext and moved it from private to public scope
Library/Homebrew/cmd/reinstall.rb	Added backup restoration for skipped formulas and added exception handler to restore all backups on any error

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[MikeMcQuaid]

Makes sense, thanks again!