- Welcome dialog buttons navigate between pages
- Done button closes dialog and marks first_run_complete
- Show welcome dialog on first launch only
- Add first_run_complete field to AppConfig with serde(default)
First-run welcome dialog with skill level and output location setup.
Desktop entry file for GNOME app launcher integration.
Nautilus Python extension with dynamic 'Process with Pixstrip' submenu
that reads both built-in and user presets.
