feat: implement dual stop system and database tracking

- Add PostgreSQL database with Prisma ORM
  - Trade model: tracks entry/exit, P&L, order signatures, config snapshots
  - PriceUpdate model: tracks price movements for drawdown analysis
  - SystemEvent model: logs errors and system events
  - DailyStats model: aggregated performance metrics

- Implement dual stop loss system (enabled by default)
  - Soft stop (TRIGGER_LIMIT) at -1.5% to avoid wicks
  - Hard stop (TRIGGER_MARKET) at -2.5% to guarantee exit
  - Configurable via USE_DUAL_STOPS, SOFT_STOP_PERCENT, HARD_STOP_PERCENT
  - Backward compatible with single stop modes

- Add database service layer (lib/database/trades.ts)
  - createTrade(): save new trades with all details
  - updateTradeExit(): close trades with P&L calculations
  - addPriceUpdate(): track price movements during trade
  - getTradeStats(): calculate win rate, profit factor, avg win/loss
  - logSystemEvent(): log errors and system events

- Update execute endpoint to use dual stops and save to database
  - Calculate dual stop prices when enabled
  - Pass dual stop parameters to placeExitOrders
  - Save complete trade record to database after execution

- Add test trade button to settings page
  - New /api/trading/test endpoint for executing test trades
  - Displays detailed results including dual stop prices
  - Confirmation dialog before execution
  - Shows entry price, position size, stops, and TX signature

- Generate Prisma client in Docker build
- Update DATABASE_URL for container networking

prisma/schema.prisma

@@ -0,0 +1,131 @@
+// Prisma Schema for Trading Bot v4
+// Database: PostgreSQL
+
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+// Trade records for analysis and performance tracking
+model Trade {
+  id        String   @id @default(cuid())
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  // Trade identification
+  positionId       String   @unique // Transaction signature from entry order
+  symbol           String   // e.g., "SOL-PERP"
+  direction        String   // "long" or "short"
+  
+  // Entry details
+  entryPrice       Float
+  entryTime        DateTime
+  entrySlippage    Float?
+  positionSizeUSD  Float
+  leverage         Float
+  
+  // Exit targets (planned)
+  stopLossPrice       Float
+  softStopPrice       Float? // Dual stop: soft stop-limit trigger
+  hardStopPrice       Float? // Dual stop: hard stop-market trigger
+  takeProfit1Price    Float
+  takeProfit2Price    Float
+  tp1SizePercent      Float
+  tp2SizePercent      Float
+  
+  // Exit details (actual)
+  exitPrice        Float?
+  exitTime         DateTime?
+  exitReason       String?  // "TP1", "TP2", "SL", "SOFT_SL", "HARD_SL", "manual", "emergency"
+  
+  // Performance metrics
+  realizedPnL      Float?
+  realizedPnLPercent Float?
+  holdTimeSeconds  Int?
+  maxDrawdown      Float?   // Peak to valley during trade
+  maxGain          Float?   // Peak gain reached
+  
+  // Order signatures
+  entryOrderTx     String
+  tp1OrderTx       String?
+  tp2OrderTx       String?
+  slOrderTx        String?
+  softStopOrderTx  String?  // Dual stop: soft stop tx
+  hardStopOrderTx  String?  // Dual stop: hard stop tx
+  exitOrderTx      String?
+  
+  // Configuration snapshot
+  configSnapshot   Json     // Store settings used for this trade
+  
+  // Signal data
+  signalSource     String?  // "tradingview", "manual", etc.
+  signalStrength   String?  // "strong", "moderate", "weak"
+  timeframe        String?  // "5", "15", "60"
+  
+  // Status
+  status           String   @default("open") // "open", "closed", "failed"
+  
+  // Relations
+  priceUpdates     PriceUpdate[]
+  
+  @@index([symbol])
+  @@index([createdAt])
+  @@index([status])
+  @@index([exitReason])
+}
+
+// Real-time price updates during trade (for analysis)
+model PriceUpdate {
+  id        String   @id @default(cuid())
+  createdAt DateTime @default(now())
+  
+  tradeId   String
+  trade     Trade    @relation(fields: [tradeId], references: [id], onDelete: Cascade)
+  
+  price     Float
+  pnl       Float
+  pnlPercent Float
+  
+  @@index([tradeId])
+  @@index([createdAt])
+}
+
+// System events and errors
+model SystemEvent {
+  id        String   @id @default(cuid())
+  createdAt DateTime @default(now())
+  
+  eventType String   // "error", "warning", "info", "trade_executed", etc.
+  message   String
+  details   Json?
+  
+  @@index([eventType])
+  @@index([createdAt])
+}
+
+// Performance analytics (daily aggregates)
+model DailyStats {
+  id        String   @id @default(cuid())
+  date      DateTime @unique
+  
+  tradesCount      Int
+  winningTrades    Int
+  losingTrades     Int
+  totalPnL         Float
+  totalPnLPercent  Float
+  winRate          Float
+  avgWin           Float
+  avgLoss          Float
+  profitFactor     Float
+  maxDrawdown      Float
+  sharpeRatio      Float?
+  
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+  
+  @@index([date])
+}