ui: Create a dedicated "Expert Mode" warning modal

[AlAfiz]

Description

When users try to toggle "Pro/Expert Mode" (which allows high slippage and disables safety prompts), we must explicitly warn them of the risks.
A simple toggle switch isn't enough; we need a blocking modal that forces them to acknowledge they can lose everything.
This protects the protocol from liability and protects novice users from themselves.
The modal should require them to type the word "EXPERT" before activating the mode.

Requirements

• Create an ExpertModeModal.tsx component.
• Trigger this modal when the user attempts to turn on the Expert toggle switch.
• Display a severe warning message about the dangers of front-running and high slippage.
• Require the user to type "EXPERT" into a text input to unlock the "Confirm" button.