Refactor DataLocationResolver to centralize data path resolution (ResolveLauncherDataPath, ResolveDesktopDataPath, ResolveConfigPath, ResolveLauncherLogsPath, ResolveLauncherStatePath) and replace usages of the previous ".launcher" layout with a "Launcher" folder. Update API: LoadConfig/SaveConfig reorganized and ApplyLocationChoice now accepts an optional custom path and migration flag; migration logic updated accordingly. Update dependent services and views (Logger, DeploymentLocator, UpdateEngineService, OobeStateService, StartupAttemptRegistry, LauncherDebugSettingsStore, OobeWindow) to use the new resolver APIs and paths. Add LauncherBackgroundService to load/validate/cache a custom splash background image and wire it into SplashWindow (AXAML/Axaml.cs) with UI placeholders and overlay. Misc: minor cleanup of Oobe/Splash XAML and related code adjustments and logging improvements.
Simplify splash startup visuals by removing the multi-mode/slide behavior and always using a fade animation. Update App to create SplashWindow without a StartupVisualMode parameter and remove related fields, layout configuration, slide animation, and easing helpers from SplashWindow. Clean up unused using. Replace the single about_banner asset with theme-aware variants (about_banner_dark.png and about_banner_light.png), delete the old about_banner.png, and update AboutSettingsPage to use a DynamicResource ImageBrush (AboutBannerBrush) that selects the appropriate banner per theme.
Implement startup visual behavior, de-duplicate startup attempts, and improve failure UX.
Key changes:
- Add spec and docs for startup visuals and timing contract (.trae/specs and docs/LAUNCHER_STARTUP_VISUALS.md).
- Introduce StartupVisualPreferences contract and resolver; create SplashWindow via resolved mode.
- Add StartupAttemptRecord model and a file-backed StartupAttemptRegistry to persist and coordinate in-progress startup attempts (attach/adopt, soft/hard timeouts, IPC/connect state, lifecycle updates).
- Update LauncherFlowCoordinator to: adopt/attach to existing attempts, track IPC connection and soft/hard timeouts (30s/120s), show delayed UI state, attempt foreground recovery via public IPC, compose detailed launch result metadata, and mark registry states (soft timeout, detached waiting, succeeded, failed).
- Add TryActivateExistingInstanceAsync to attempt activating an existing desktop via IPC.
- Change failure flow: ShowFailureWindowAsync now returns user choice; ErrorWindow updated to present Activate/Wait/Open Logs/Exit semantics and new layouts/styles; improved button wiring and debug/dev mode handling.
- Add UI and resource tweaks (ErrorWindow and SplashWindow changes), project asset link for nightly logo, and unit tests for StartupVisualPreferences.
These changes prevent duplicate desktop processes during slow startups, provide clearer UX for delayed startups, and persist startup attempt state across Launcher invocations for safer recovery/attach behavior.
