feat(frontend): add React dashboard with TypeScript

Add modern React frontend to replace Streamlit dashboard:
- Vite build system with TypeScript
- Tailwind CSS for styling
- Component structure in src/
- Production Dockerfile with nginx
- Development server on port 5173

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/types/index.ts

@@ -0,0 +1,46 @@
+export interface User {
+  id: number;
+  email: string;
+  role: 'admin' | 'user';
+  created_at: string;
+}
+
+export interface TokenResponse {
+  access_token: string;
+  refresh_token: string;
+  token_type: string;
+}
+
+export interface CompanyAnalysis {
+  company_name: string;
+  analysis: string;
+  patent_count: number;
+  success: boolean;
+  error: string | null;
+  timestamp: string;
+}
+
+export interface BatchAnalysisResult {
+  results: CompanyAnalysis[];
+  total_companies: number;
+  successful: number;
+  failed: number;
+  timestamp: string;
+}
+
+export interface JobStatus {
+  job_id: string;
+  status: 'pending' | 'running' | 'completed' | 'failed';
+  progress: number;
+  total_companies: number;
+  completed_companies: number;
+  result: BatchAnalysisResult | null;
+  error: string | null;
+}
+
+export interface Analytics {
+  total_messages: number;
+  by_company: Array<{ company_name: string; count: number }>;
+  by_type: Array<{ analysis_type: string; count: number }>;
+  period_days: number;
+}