[Enhancement] Complete frontend re-design and UI responsiveness Issues

[khushal1512]

Context

Following the core architectural changes and LangGraph setup completed in PR #124, we need to focus on the frontend implementation.

Problem

1. Lack of Identity: The current UI lacks a distinct brand identity and looks like a generic, AI-generated template. It does not reflect the project's design language.
2. Disconnected Backend: The frontend currently runs on hardcoded mock data and does not communicate with the FastAPI backend.
3. Responsiveness: The layout breaks on mobile devices (overlapping sidebars, hidden menus).

Solution

• UI Overhaul: Replace the current generic interface with the custom design shared in the Discord channel (Figma).
• Integration: Connect the PerspectivePage to the real /api/bias and /api/process endpoints.
• Mobile Support: Implement a fully responsive layout with collapsible sidebars and hamburger menus.

Tasks

• Implement pixel-perfect Landing Page from Figma.
• Build BiasGauge and RightSidebar components matching the new design.
• Create usePerspective hook for real-time API data fetching.
• Fix NLTK threading crashes in the backend to support the new frontend requests.

[khushal1512]

@ParagGhatage please can you assign me this issue