feat(notifications): implement administrative manual notifications dashboard

[CrazzyBuilds]

Description

This Pull Request introduces the Manual Notifications Dashboard within the Admin portal. It adds the page layout, integrates dynamic auto-complete search with tag badges for specific user targeting, upgrades the core UI library dependency, and configures unified Vitest mock environments.

Key Changes

• Dashboard Interface: Implemented the NotificationsAdminPage allowing administrators to manual dispatch broadcast, role-based, or user-based alerts.
• Search & Badges Component: Integrated a searchable auto-complete dropdown to filter users by name/email, displaying selections as individual tag badges.
• Shared Library Upgrade: Upgraded @variamosple/variamos-components to the clean registry version ^0.2.2.
• Vitest & Vite Configs: Unified UI mocks inside setupTests.ts and configured strict local resolving aliases inside vitest.config.mts to prevent duplicate React runtime instances.
• Test Suite: Added page unit tests in NotificationsAdminPage.test.tsx and Playwright mocked and real E2E scripts under tests/notifications/.

How to Test

1. Run npm run typecheck and npm run lint:fix to verify compilation and styling consistency.
2. Open the admin portal at /admin/notifications, type a username, select it, fill out the form, and verify the green success alert banner.
3. Run the Playwright test suite to verify mocked and real E2E flows.