The NSIS upgrade path runs the previous version's uninstaller before
reinstalling, and that uninstaller deleted the per-user HKCU Run value that
the UI's Wails autostart toggle owns. As a result every EXE-based auto-update
silently wiped the user's launch-on-login choice. Stop deleting the HKCU
value on uninstall; a leftover entry after a genuine uninstall is harmless
since Windows ignores Run values whose target no longer exists. The legacy
machine-wide HKLM entry is still cleaned up.