feat(admin_ui): enhance Admin Console with improved plugin management and user guidance

- Removed the outdated project warning from AGENTS.md to streamline the introduction.
- Updated the App component to always include the Plugins tab, ensuring users can access it regardless of feature status.
- Enhanced the Plugins component to check if the v3 plugin feature is enabled, providing users with an alert if it is disabled, guiding them to enable it in settings.
- Improved the Inbound component by removing an unused anchor function, simplifying the code.

These changes enhance the usability and clarity of the Admin Console, making it easier for users to manage plugins and access relevant features.

Author: Faxbot Agent