[Improvement] Redesign the menu #258

Summary

Replace the current top bar menu with a sidebar navigation to improve structure, scalability, and usability of the dashboard.

Problem

The existing top bar menu limits space and can become crowded as more features and pages are added. It also makes it harder to clearly organize and display sub page items, reducing overall navigation clarity.

Proposed Solution

Introduce a sidebar navigation that:

• Organizes main sections vertically for better scalability
• Supports nested items to clearly display sub pages
• Improves visibility and accessibility of all navigation options
• Allows collapsing/expanding sections for cleaner navigation