[Frontend/UI] Implement Navbar Component

[Amarjeet325]

Background/Context

We need to implement the main Navigation Bar for the Alien Protocol landing page based on the new simplified UI design.

Detailed Tasks Checklist

• Create a responsive Navbar component.
• Include the alien favicon and "ALIEN PROTOCOL" text on the left.
• NO navigation links in the center.
• Include a "LAUNCH APP" button on the right (with a rocket icon).
• Ensure the component follows the dark theme.

Acceptance Criteria

• Fixed at the top, responsive.