feat: enhance test setup with splash screen handling and sandbox warnings

- Added `skipSandboxWarning` option to project setup functions to streamline testing.
- Implemented logic to disable the splash screen during tests by setting `automaker-splash-shown` in sessionStorage.
- Introduced a new package.json for a test project and added a test image to the fixtures for improved testing capabilities.

apps/ui/tests/utils/project/fixtures.ts

@@ -89,6 +89,7 @@ export async function setupProjectWithFixture(
         currentView: 'board',
         theme: 'dark',
         sidebarOpen: true,
+        skipSandboxWarning: true,
         apiKeys: { anthropic: '', google: '' },
         chatSessions: [],
         chatHistoryOpen: false,