Fix Welcome Modal Rerendering

[Faisalmajeed123]

This PR updates the welcome modal logic to ensure it only appears on the first visit by storing a flag in local storage. Previously, the modal would show up every time the page reloaded, negatively impacting the user experience and forcing users to close the modal repeatedly. This fix improves user experience by making it a one-time welcome, improving usability, and reducing unnecessary interruptions.

What's Changed:

• Added local storage check to track if the user has already seen the modal.
• The modal only renders on the first visit and stays hidden afterward.

How to Test:

• Open the app—the welcome modal should appear.
• Refresh the page—the modal should NOT show again.
• Clear local storage and refresh—the modal should reappear.

This small tweak makes the onboarding experience much smoother!