refactor(frontend): replace useAsyncTask with TanStack Query

[ivanskv2000]

✨ What’s Changed?

This pull request completes a refactor of the frontend's asynchronous state management. The custom useAsyncTask composable has been replaced with useQuery and useMutation hooks from TanStack Query.

• Standardized Data Fetching: All asynchronous operations (login, signup, data import/export, seeding, etc.) now use a consistent, declarative pattern.
• Improved State Management: Leverages TanStack Query's built-in handling for loading, error, and success states.
• Code Deletion: The useAsyncTask.ts composable has been removed, simplifying the codebase.
• Enhanced Reactivity: Mutations that change server data (e.g., import, seed, reset) now use queryClient.invalidateQueries() to automatically refetch stale data and keep the UI in sync across the application.

Affected Components:

• All module pages, e. g. EventCreatePage.vue, EventDetailsPage.vue, EventsPage.vue
• LoginForm.vue, SignupForm.vue
• Switchboard panels: ResetPanel.vue, SeedPanel.vue, ImportPanel.vue, ExportPanel.vue
• SwaggerExportModal.vue

📂 Scope

• frontend
• backend
• common/shared
• CI/config

[sonarqubecloud]

Quality Gate passed

Issues
33 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
1.8% Duplication on New Code

See analysis details on SonarQube Cloud