refactor: remove all backtest module code and references

Delete backtest/ engine (19 files), api/backtest.go, store/backtest.go,
web backtest components (7 files), API client, types, docs, screenshot.
Clean all backtest references from main.go, api/server.go, store/store.go,
App.tsx, HeaderBar.tsx, LandingPage.tsx, translations, README and docs.

web/src/types/backtest.ts

@@ -1,167 +0,0 @@
-// Backtest types
-export interface BacktestRunSummary {
-  symbol_count: number;
-  decision_tf: string;
-  processed_bars: number;
-  progress_pct: number;
-  equity_last: number;
-  max_drawdown_pct: number;
-  liquidated: boolean;
-  liquidation_note?: string;
-}
-
-export interface BacktestRunMetadata {
-  run_id: string;
-  label?: string;
-  user_id?: string;
-  last_error?: string;
-  version: number;
-  state: string;
-  created_at: string;
-  updated_at: string;
-  summary: BacktestRunSummary;
-}
-
-export interface BacktestRunsResponse {
-  total: number;
-  items: BacktestRunMetadata[];
-}
-
-// Position status for real-time display during backtest
-export interface BacktestPositionStatus {
-  symbol: string;
-  side: string;
-  quantity: number;
-  entry_price: number;
-  mark_price: number;
-  leverage: number;
-  unrealized_pnl: number;
-  unrealized_pnl_pct: number;
-  margin_used: number;
-}
-
-export interface BacktestStatusPayload {
-  run_id: string;
-  state: string;
-  progress_pct: number;
-  processed_bars: number;
-  current_time: number;
-  decision_cycle: number;
-  equity: number;
-  unrealized_pnl: number;
-  realized_pnl: number;
-  positions?: BacktestPositionStatus[];
-  note?: string;
-  last_error?: string;
-  last_updated_iso: string;
-}
-
-export interface BacktestEquityPoint {
-  ts: number;
-  equity: number;
-  available: number;
-  pnl: number;
-  pnl_pct: number;
-  dd_pct: number;
-  cycle: number;
-}
-
-export interface BacktestTradeEvent {
-  ts: number;
-  symbol: string;
-  action: string;
-  side?: string;
-  qty: number;
-  price: number;
-  fee: number;
-  slippage: number;
-  order_value: number;
-  realized_pnl: number;
-  leverage?: number;
-  cycle: number;
-  position_after: number;
-  liquidation: boolean;
-  note?: string;
-}
-
-export interface BacktestMetrics {
-  total_return_pct: number;
-  max_drawdown_pct: number;
-  sharpe_ratio: number;
-  profit_factor: number;
-  win_rate: number;
-  trades: number;
-  avg_win: number;
-  avg_loss: number;
-  best_symbol: string;
-  worst_symbol: string;
-  liquidated: boolean;
-  symbol_stats?: Record<
-    string,
-    {
-      total_trades: number;
-      winning_trades: number;
-      losing_trades: number;
-      total_pnl: number;
-      avg_pnl: number;
-      win_rate: number;
-    }
-  >;
-}
-
-export interface BacktestStartConfig {
-  run_id?: string;
-  ai_model_id?: string;
-  strategy_id?: string; // Optional: use saved strategy from Strategy Studio
-  symbols: string[];
-  timeframes: string[];
-  decision_timeframe: string;
-  decision_cadence_nbars: number;
-  start_ts: number;
-  end_ts: number;
-  initial_balance: number;
-  fee_bps: number;
-  slippage_bps: number;
-  fill_policy: string;
-  prompt_variant?: string;
-  prompt_template?: string;
-  custom_prompt?: string;
-  override_prompt?: boolean;
-  cache_ai?: boolean;
-  replay_only?: boolean;
-  checkpoint_interval_bars?: number;
-  checkpoint_interval_seconds?: number;
-  replay_decision_dir?: string;
-  shared_ai_cache_path?: string;
-  ai?: {
-    provider?: string;
-    model?: string;
-    key?: string;
-    secret_key?: string;
-    base_url?: string;
-  };
-  leverage?: {
-    btc_eth_leverage?: number;
-    altcoin_leverage?: number;
-  };
-}
-
-// Kline data for backtest chart
-export interface BacktestKline {
-  time: number;
-  open: number;
-  high: number;
-  low: number;
-  close: number;
-  volume: number;
-}
-
-export interface BacktestKlinesResponse {
-  symbol: string;
-  timeframe: string;
-  start_ts: number;
-  end_ts: number;
-  count: number;
-  klines: BacktestKline[];
-  run_id: string;
-}

web/src/types/index.ts

@@ -1,4 +1,3 @@
 export * from './trading'
-export * from './backtest'
 export * from './strategy'
 export * from './config'