fix: correct LP fee from 3% to 0.3%

Runtime LPFee = 3 means 3/1000 = 0.3%, not 3%.
Updated AMM calculations in TokenSwap, SwapInterface, and PoolDashboard.

web/src/components/PoolDashboard.tsx

@@ -290,7 +290,7 @@ const PoolDashboard = () => {
     // This is a simplified calculation
     // Real APR = (24h fees × 365) / TVL
     const dailyVolumeEstimate = totalLiquidityUSD * 0.1; // Assume 10% daily turnover
-    const dailyFees = dailyVolumeEstimate * 0.03; // 3% fee
+    const dailyFees = dailyVolumeEstimate * 0.003; // 0.3% fee
     const annualFees = dailyFees * 365;
     const apr = (annualFees / totalLiquidityUSD) * 100;
 

web/src/components/TokenSwap.tsx

@@ -105,10 +105,10 @@ const TokenSwap = () => {
     const reserveOut = isAsset0ToAsset1 ? reserve1 : reserve0;
 
     // Uniswap V2 AMM formula (matches Substrate runtime exactly)
-    // Runtime: amount_in_with_fee = amount_in * (1000 - LPFee) = amount_in * 970
-    // LPFee = 30 (3% fee, not 0.3%!)
-    // Formula: amountOut = (amountIn * 970 * reserveOut) / (reserveIn * 1000 + amountIn * 970)
-    const LP_FEE = 30; // 3% fee
+    // Runtime: amount_in_with_fee = amount_in * (1000 - LPFee) = amount_in * 997
+    // LPFee = 3 (0.3% fee - standard DEX fee)
+    // Formula: amountOut = (amountIn * 997 * reserveOut) / (reserveIn * 1000 + amountIn * 997)
+    const LP_FEE = 3; // 0.3% fee
     const amountInWithFee = amountIn * (1000 - LP_FEE); // = amountIn * 970
     const numerator = amountInWithFee * reserveOut;
     const denominator = reserveIn * 1000 + amountInWithFee;

web/src/components/dex/SwapInterface.tsx

@@ -135,7 +135,7 @@ export const SwapInterface: React.FC<SwapInterfaceProps> = ({ pools }) => {
       const reserveIn = isForward ? activePool.reserve1 : activePool.reserve2;
       const reserveOut = isForward ? activePool.reserve2 : activePool.reserve1;
 
-      const toAmountRaw = getAmountOut(fromAmountRaw, reserveIn, reserveOut, 30); // 3% fee
+      const toAmountRaw = getAmountOut(fromAmountRaw, reserveIn, reserveOut, 3); // 0.3% fee
       const toAmountDisplay = formatTokenBalance(toAmountRaw, toTokenInfo.decimals, 6);
 
       setToAmount(toAmountDisplay);