Billing & Subscriptions revamp

Billing & Subscription moved to main sidebar for easier access.

Billing & Subscription is currently nested inside the Admin Panel, making it hard to find. Since billing is a workspace-level concern that spans across all products, it will now be available as a dedicated sidebar item so owners can access and manage their plans from one consistent place, regardless of which product they are in.

Existing UI - https://praveen-murali.neetocal.com/admin/admin-panel

Existing NeetoAuth - https://praveen-murali.neetoauth.com/admin/billing