Add React frontend for energy trading system

Implements React + TypeScript UI with Vite and Tailwind CSS.
Features dashboard with real-time WebSocket updates, backtesting
page, model management interface, trading controls, and settings.
Includes state management with Zustand, API integration with
Axios/TanStack Query, and interactive charts with Recharts.

frontend/src/lib/constants.ts

@@ -0,0 +1,65 @@
+import type { Region, Strategy, TradeType, BacktestStatus, ModelType, TrainingStatus, AlertType } from '@/services/types';
+
+export const REGIONS: Region[] = ['FR', 'BE', 'DE', 'NL', 'UK'];
+
+export const STRATEGIES: Strategy[] = ['fundamental', 'technical', 'ml', 'mining'];
+
+export const TRADE_TYPES: TradeType[] = ['buy', 'sell', 'charge', 'discharge'];
+
+export const BACKTEST_STATUSES: BacktestStatus[] = ['pending', 'running', 'completed', 'failed', 'cancelled'];
+
+export const MODEL_TYPES: ModelType[] = ['price_prediction', 'rl_battery'];
+
+export const TRAINING_STATUSES: TrainingStatus[] = ['pending', 'running', 'completed', 'failed'];
+
+export const ALERT_TYPES: AlertType[] = ['price_spike', 'arbitrage_opportunity', 'battery_low', 'battery_full', 'strategy_error'];
+
+export const REGION_LABELS: Record<Region, string> = {
+  FR: 'France',
+  BE: 'Belgium',
+  DE: 'Germany',
+  NL: 'Netherlands',
+  UK: 'United Kingdom',
+};
+
+export const STRATEGY_LABELS: Record<Strategy, string> = {
+  fundamental: 'Fundamental',
+  technical: 'Technical',
+  ml: 'ML Based',
+  mining: 'Mining',
+};
+
+export const TRADE_TYPE_LABELS: Record<TradeType, string> = {
+  buy: 'Buy',
+  sell: 'Sell',
+  charge: 'Charge',
+  discharge: 'Discharge',
+};
+
+export const BACKTEST_STATUS_LABELS: Record<BacktestStatus, string> = {
+  pending: 'Pending',
+  running: 'Running',
+  completed: 'Completed',
+  failed: 'Failed',
+  cancelled: 'Cancelled',
+};
+
+export const MODEL_TYPE_LABELS: Record<ModelType, string> = {
+  price_prediction: 'Price Prediction',
+  rl_battery: 'RL Battery',
+};
+
+export const TRAINING_STATUS_LABELS: Record<TrainingStatus, string> = {
+  pending: 'Pending',
+  running: 'Running',
+  completed: 'Completed',
+  failed: 'Failed',
+};
+
+export const ALERT_TYPE_LABELS: Record<AlertType, string> = {
+  price_spike: 'Price Spike',
+  arbitrage_opportunity: 'Arbitrage Opportunity',
+  battery_low: 'Battery Low',
+  battery_full: 'Battery Full',
+  strategy_error: 'Strategy Error',
+};