🎨 Frontend: Chat Interface & Course Preview

## Phase 1: MVP User Interface

Build the conversational UI for course creation and preview.

### Tasks
- [ ] Build "Chat Interface" for initial course negotiation
- [ ] Implement streaming responses from backend
- [ ] Build "Course Preview" card (Syllabus tree view)
- [ ] Create expandable Topic/Subtopic components
- [ ] Add video count and duration estimates per section
- [ ] Integration: Connect Frontend to Python Backend APIs

### Acceptance Criteria
- Clean chat interface with message history
- Real-time streaming of AI responses
- Interactive syllabus preview showing hierarchy
- Ability to edit/regenerate topics before finalizing
- Responsive design (mobile + desktop)

### Tech Stack
- React 18 + Vite
- Tailwind CSS
- Zustand/Redux for state management
- React Query for API calls
- Framer Motion for animations