fix(compilation): resolve type system and interface errors

- Add GetPoolsByToken method to cache interface and implementation
- Fix interface pointer types (use interface not *interface)
- Fix SwapEvent.TokenIn/TokenOut usage to use GetInputToken/GetOutputToken methods
- Fix ethereum.CallMsg import and usage
- Fix parser factory and validator initialization in main.go
- Remove unused variables and imports

WIP: Still fixing main.go config struct field mismatches

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

pkg/execution/executor.go

@@ -232,7 +232,7 @@ func (e *Executor) Execute(ctx context.Context, opp *arbitrage.Opportunity) (*Ex
 
 	// Calculate actual profit
 	actualProfit := e.calculateActualProfit(receipt, opp)
-	gasCost := new(big.Int).Mul(receipt.GasUsed, receipt.EffectiveGasPrice)
+	gasCost := new(big.Int).Mul(big.NewInt(int64(receipt.GasUsed)), receipt.EffectiveGasPrice)
 
 	result := &ExecutionResult{
 		Success:      receipt.Status == types.ReceiptStatusSuccessful,