Extract three focused modules from run.go and mainwindow.go:
- tray.go: configureSystemTray() and related tray setup
- singleinstance.go: acquireSingleInstance(), serveSingleInstance(), and constants
- layout.go: minWidthLayout type and methods
No behavior change; purely mechanical extraction to improve file organization.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
mixeme