installer-v1.2.0

Added

• Mouse support, terminal resize handling, and Ctrl+L / Repair TUI to
  refresh a broken display in the installer.
• GoReleaser release pipeline for installer-v* tags: .tar.gz / .zip
  archives, checksums.txt, and release notes taken from ### changelog
  sections.

Changed

• Reworked the installer TUI for clearer layout and navigation: left-side
  selection marks, full-width selection highlighting, tighter footers, and a
  sectioned keybindings screen (?).
• Manage screen actions and shortcuts reorganized for faster day-to-day use.
• Installer downloads are release archives (extract, then run cursor-utils)
  rather than bare binaries.