Superset: Implement custom UI navigation and Keycloak integration for FASE

**Overview**
Apache Superset has been selected as the frontend replacement for our legacy reporting tool (#283). To replicate the legacy user access model and provide a streamlined user experience, we need to customize Superset to show users only the minimum necessary menus and navigation options.
This issue tracks the customization required for Superset to access and navigate FASE application data from the lakehouse.

**Tasks**
- [ ] Navigation: Build menu-driven navigation — relates to #294
- [ ] UX Enhancement: Build 'Favorites + Recent Activities' section — relates to #301
- [ ] Security: Integrate Keycloak to secure role-based user access (RBAC) — relates to #223
- [ ] Infrastructure: Build a separate, dedicated Superset environment setup for FASE