fix(multicall): resolve critical multicall parsing corruption issues

- Added comprehensive bounds checking to prevent buffer overruns in multicall parsing
- Implemented graduated validation system (Strict/Moderate/Permissive) to reduce false positives
- Added LRU caching system for address validation with 10-minute TTL
- Enhanced ABI decoder with missing Universal Router and Arbitrum-specific DEX signatures
- Fixed duplicate function declarations and import conflicts across multiple files
- Added error recovery mechanisms with multiple fallback strategies
- Updated tests to handle new validation behavior for suspicious addresses
- Fixed parser test expectations for improved validation system
- Applied gofmt formatting fixes to ensure code style compliance
- Fixed mutex copying issues in monitoring package by introducing MetricsSnapshot
- Resolved critical security vulnerabilities in heuristic address extraction
- Progress: Updated TODO audit from 10% to 35% complete

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

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

pkg/types/types.go

@@ -3,6 +3,7 @@ package types
 
 import (
 	"math/big"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 )
@@ -10,22 +11,49 @@ import (
 // ArbitrageOpportunity represents a potential arbitrage opportunity
 // This is the canonical definition used across all packages
 type ArbitrageOpportunity struct {
-	Path          []string       // Token path for the arbitrage
-	Pools         []string       // Pools involved in the arbitrage
-	AmountIn      *big.Int       // Input amount for the arbitrage
-	Profit        *big.Int       // Estimated profit in wei
-	NetProfit     *big.Int       // Net profit after gas costs
-	GasEstimate   *big.Int       // Estimated gas cost
-	ROI           float64        // Return on investment percentage
-	Protocol      string         // DEX protocol
-	ExecutionTime int64          // Estimated execution time in milliseconds
-	Confidence    float64        // 0-1 confidence score
-	PriceImpact   float64        // Price impact percentage
-	MaxSlippage   float64        // Maximum acceptable slippage
-	TokenIn       common.Address // Input token address
-	TokenOut      common.Address // Output token address
-	Timestamp     int64          // Detection timestamp
-	Risk          float64        // Risk assessment score (0-1)
+	ID              string                 // Unique identifier for the opportunity
+	Path            []string               // Token path for the arbitrage
+	Pools           []string               // Pools involved in the arbitrage
+	AmountIn        *big.Int               // Input amount for the arbitrage (wei)
+	Profit          *big.Int               // Estimated gross profit in wei
+	NetProfit       *big.Int               // Net profit after gas costs in wei
+	GasEstimate     *big.Int               // Estimated gas usage cost in wei
+	GasCost         *big.Int               // Calculated gas cost in wei (optional)
+	EstimatedProfit *big.Int               // Cached estimated profit in wei
+	RequiredAmount  *big.Int               // Capital required to execute in wei
+	ROI             float64                // Return on investment percentage
+	Protocol        string                 // DEX protocol
+	ExecutionTime   int64                  // Estimated execution time in milliseconds
+	Confidence      float64                // 0-1 confidence score
+	PriceImpact     float64                // Price impact percentage
+	MaxSlippage     float64                // Maximum acceptable slippage percentage
+	TokenIn         common.Address         // Input token address
+	TokenOut        common.Address         // Output token address
+	Timestamp       int64                  // Detection timestamp (unix seconds)
+	DetectedAt      time.Time              // Detection timestamp with higher precision
+	ExpiresAt       time.Time              // Expiration timestamp
+	Urgency         int                    // Relative urgency (1-10)
+	Risk            float64                // Risk assessment score (0-1)
+	Profitable      bool                   // Indicates if opportunity is currently profitable
+	Quantities      *OpportunityQuantities // Optional UniversalDecimal snapshots
+}
+
+// DecimalAmount serialises a decimal quantity without importing math helpers.
+type DecimalAmount struct {
+	Value    string `json:"value"`
+	Decimals uint8  `json:"decimals"`
+	Symbol   string `json:"symbol"`
+}
+
+// OpportunityQuantities bundles the primary decimal metrics for an opportunity.
+type OpportunityQuantities struct {
+	AmountIn      DecimalAmount `json:"amount_in"`
+	AmountOut     DecimalAmount `json:"amount_out"`
+	GrossProfit   DecimalAmount `json:"gross_profit"`
+	NetProfit     DecimalAmount `json:"net_profit"`
+	GasCost       DecimalAmount `json:"gas_cost"`
+	ProfitPercent DecimalAmount `json:"profit_percentage"`
+	PriceImpact   DecimalAmount `json:"price_impact"`
 }
 
 // PriceMovement represents a potential price movement