feat: Add per-symbol trading controls for SOL and ETH

- Add SymbolSettings interface with enabled/positionSize/leverage fields
- Implement per-symbol ENV variables (SOLANA_*, ETHEREUM_*)
- Add SOL and ETH sections to settings UI with enable/disable toggles
- Add symbol-specific test buttons (SOL LONG/SHORT, ETH LONG/SHORT)
- Update execute and test endpoints to check symbol enabled status
- Add real-time risk/reward calculator per symbol
- Rename 'Position Sizing' to 'Global Fallback' for clarity
- Fix position manager P&L calculation for externally closed positions
- Fix zero P&L bug affecting 12 historical trades
- Add SQL scripts for recalculating historical P&L data
- Move archive TypeScript files to .archive to fix build

Defaults:
- SOL: 10 base × 10x leverage = 100 notional (profit trading)
- ETH:  base × 1x leverage =  notional (data collection)
- Global: 10 × 10x for BTC and other symbols

Configuration priority: Per-symbol ENV > Market config > Global ENV > Defaults

app/api/settings/route.ts

@@ -62,8 +62,19 @@ export async function GET() {
     const env = parseEnvFile()
     
     const settings = {
+      // Global fallback
       MAX_POSITION_SIZE_USD: parseFloat(env.MAX_POSITION_SIZE_USD || '50'),
       LEVERAGE: parseFloat(env.LEVERAGE || '5'),
+      
+      // Per-symbol settings
+      SOLANA_ENABLED: env.SOLANA_ENABLED !== 'false',
+      SOLANA_POSITION_SIZE: parseFloat(env.SOLANA_POSITION_SIZE || '210'),
+      SOLANA_LEVERAGE: parseFloat(env.SOLANA_LEVERAGE || '10'),
+      ETHEREUM_ENABLED: env.ETHEREUM_ENABLED !== 'false',
+      ETHEREUM_POSITION_SIZE: parseFloat(env.ETHEREUM_POSITION_SIZE || '4'),
+      ETHEREUM_LEVERAGE: parseFloat(env.ETHEREUM_LEVERAGE || '1'),
+      
+      // Risk management
       STOP_LOSS_PERCENT: parseFloat(env.STOP_LOSS_PERCENT || '-1.5'),
       TAKE_PROFIT_1_PERCENT: parseFloat(env.TAKE_PROFIT_1_PERCENT || '0.7'),
       TAKE_PROFIT_1_SIZE_PERCENT: parseFloat(env.TAKE_PROFIT_1_SIZE_PERCENT || '50'),