Replace the in-memory loadConfig() stub with real ~/.core/gui/config.yaml
loading via go-config. handleConfigTask now persists changes to disk via
cfg.Set() + cfg.Commit(). Sub-service applyConfig() stubs fleshed out:
window reads default dimensions (TODO: Manager API), systray stores icon
path, menu reads show_dev_tools flag with accessor.
Co-Authored-By: Virgil <virgil@lethean.io>
Display HandleIPCEvents converts sub-service actions to WS events.
ActionServiceStartup triggers buildMenu/setupTray after all services start.
Export mock platforms from each sub-package for integration tests.
Co-Authored-By: Virgil <virgil@lethean.io>
Systray package is now a full core.Service with typed IPC messages.
Menu item clicks emit ActionTrayMenuItemClicked via IPC.
Co-Authored-By: Virgil <virgil@lethean.io>
