ui: Design a "Connect Wallet" empty state for the dashboard

[AlAfiz]

Description

If a user lands on the portfolio or swap page without their wallet connected, the UI looks broken because the data is missing.
We need a beautiful, centralized empty state that clearly tells them to connect their wallet to proceed.
This state should replace the charts and tables with a single, highly visible call to action.
Good empty states are the difference between a prototype and a real product.

Requirements

• Create a WalletNotConnected.tsx component.
• Render a large wallet icon (SVG) in the center of the screen with a subtle glow effect.
• Add a bold title: "Connect your wallet to start trading".
• Render the primary <Button> component underneath that triggers the wallet connection modal.