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/orchestrator/coordinator.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+
 	"github.com/fraktal/mev-beta/internal/config"
 	"github.com/fraktal/mev-beta/internal/logger"
 	"github.com/fraktal/mev-beta/pkg/arbitrage"
@@ -35,7 +36,7 @@ type MEVCoordinator struct {
 	rawTransactions chan *RawTransaction
 	parsedEvents    chan *events.Event
 	poolUpdates     chan *PoolUpdate
-	arbitrageOppCh  chan *ArbitrageOpportunity
+	arbitrageOppCh  chan *OrchestratorOpportunity
 
 	// Coordination
 	wg     sync.WaitGroup
@@ -65,6 +66,14 @@ type PoolUpdate struct {
 }
 
 // Use the canonical ArbitrageOpportunity from types package
+type OrchestratorOpportunity struct {
+	Paths        []*arbitrage.ArbitragePath
+	TriggerToken common.Address
+	Amount       *big.Int
+	NetProfit    *big.Int
+	ROI          float64
+	DetectedAt   time.Time
+}
 
 // CoordinatorMetrics tracks performance metrics
 type CoordinatorMetrics struct {
@@ -103,7 +112,7 @@ func NewMEVCoordinator(
 		rawTransactions: make(chan *RawTransaction, config.Bot.ChannelBufferSize),
 		parsedEvents:    make(chan *events.Event, config.Bot.ChannelBufferSize),
 		poolUpdates:     make(chan *PoolUpdate, config.Bot.ChannelBufferSize),
-		arbitrageOppCh:  make(chan *ArbitrageOpportunity, 100),
+		arbitrageOppCh:  make(chan *OrchestratorOpportunity, 100),
 
 		ctx:     ctx,
 		cancel:  cancel,
@@ -356,7 +365,7 @@ func (mc *MEVCoordinator) triggerArbitrageScan(event *events.Event) {
 				totalProfit.Add(totalProfit, path.NetProfit)
 			}
 
-			opportunity := &ArbitrageOpportunity{
+			opportunity := &OrchestratorOpportunity{
 				Paths:        paths,
 				TriggerToken: triggerToken,
 				Amount:       amount,
@@ -431,7 +440,7 @@ func (mc *MEVCoordinator) startOpportunityHandler() {
 }
 
 // handleArbitrageOpportunity handles a detected arbitrage opportunity
-func (mc *MEVCoordinator) handleArbitrageOpportunity(opp *ArbitrageOpportunity) {
+func (mc *MEVCoordinator) handleArbitrageOpportunity(opp *OrchestratorOpportunity) {
 	mc.logger.Info(fmt.Sprintf("🎯 ARBITRAGE OPPORTUNITY DETECTED!"))
 	mc.logger.Info(fmt.Sprintf("  Token: %s", opp.TriggerToken.Hex()))
 	mc.logger.Info(fmt.Sprintf("  Amount: %s wei", opp.Amount.String()))