fix: dashboard metrics — real drawdown baseline, realized/unrealized split, risk radar fields

- Max drawdown was double-broken: the backend built the equity curve on a
  hardcoded $10k baseline (understating a small account's drawdown ~20x) and
  the frontend multiplied the already-percent value by 100 again (0.87% shown
  as -86.9%). The curve now starts from the trader's real initial balance
  (10k fallback when unknown) and the UI renders the percent once; the demo
  engine and type docs are aligned to percent semantics.
- Header now separates equity-based 'Total P/L (incl. unrealized)' from
  'Realized P/L (closed trades)' so it no longer contradicts profit factor /
  win rate, and the stats strip shows the fee-drag chain
  (gross - fees = net) plus a per-trade-labelled sharpe.
- Risk radar read a non-existent account field (total_unrealized_profit) so
  unrealized PnL always showed $0; small PnLs also render with cents now.
- Nav 'Connect Hyperliquid' turns into a green connected chip when the server
  already holds a fully-authorized exchange, instead of nagging forever from
  a browser without the localStorage flow state.

trader/auto_trader.go

@@ -612,6 +612,12 @@ func (at *AutoTrader) GetID() string {
 	return at.id
 }
 
+// GetInitialBalance returns the account baseline used for performance metrics
+// (e.g. the drawdown equity curve).
+func (at *AutoTrader) GetInitialBalance() float64 {
+	return at.initialBalance
+}
+
 // GetUnderlyingTrader returns the underlying Trader interface implementation
 // This is used by grid trading and other components that need direct exchange access
 func (at *AutoTrader) GetUnderlyingTrader() Trader {

trader/auto_trader_loop.go

@@ -652,7 +652,7 @@ func (at *AutoTrader) buildTradingContext() (*kernel.Context, error) {
 			}
 		}
 		// Get trading statistics for AI context
-		stats, err := at.store.Position().GetFullStats(at.id)
+		stats, err := at.store.Position().GetFullStats(at.id, at.initialBalance)
 		if err != nil {
 			at.logWarnf("⚠️ Failed to get trading stats: %v", err)
 		} else if stats == nil {