fix(admin-ui): Integrate SQL Client with CodeMirror Editor into Admin UI

# SQL Client Integration in Admin UI

## Description
We need to embed an SQL client directly within the Admin UI to allow users to execute SQL queries and manage database configurations more efficiently without relying on external tools.

This feature will improve the user experience, especially for users managing custom attributes and operating in restricted environments where direct DB access is limited.

## Goals
- Integrate **CodeMirror v6** as the SQL editor in the Admin UI.
- Add a new **“SQL Studio”** tab in the Admin sidebar for accessing the SQL client.
- Support running common SQL commands (`SELECT`, `INSERT`, `UPDATE`, `ALTER`, `DELETE`) with syntax highlighting and basic autocomplete.
- Display query results or errors clearly in the UI.

## Requirements / Details
- The frontend editor will send SQL queries to a backend API endpoint (to be developed separately).
- The backend will securely execute the queries and return results.
- RBAC will be enforced by the backend (using Cedarling); the frontend should reflect permissions where possible (e.g., disabling controls for unauthorized users).
- Limit the number of rows returned/displayed by default to maintain UI responsiveness (e.g., max 100 rows).
- The **“SQL Studio”** tab should be placed under the Admin section in the sidebar.