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>

tools/performance-audit/go.mod

@@ -0,0 +1,7 @@
+module github.com/fraktal/mev-beta/tools/performance-audit
+
+go 1.24
+
+replace github.com/fraktal/mev-beta => ../../
+
+require github.com/fraktal/mev-beta v0.0.0-00010101000000-000000000000

tools/performance-audit/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/fraktal/mev-beta/tools/performance-audit/internal"
+)
+
+func main() {
+	var (
+		testType       = flag.String("test", "all", "Test type: throughput, latency, memory, cpu, stress, all")
+		duration       = flag.Duration("duration", 5*time.Minute, "Test duration")
+		outputDir      = flag.String("output", "reports/performance", "Output directory")
+		verbose        = flag.Bool("verbose", false, "Enable verbose output")
+		concurrent     = flag.Int("concurrent", 10, "Number of concurrent workers")
+		loadLevel      = flag.String("load", "normal", "Load level: light, normal, heavy, extreme")
+		profileEnabled = flag.Bool("profile", false, "Enable CPU/memory profiling")
+		benchmarkMode  = flag.Bool("benchmark", false, "Run in benchmark mode")
+		stressTest     = flag.Bool("stress", false, "Run stress test scenarios")
+		targetTPS      = flag.Int("target-tps", 1000, "Target transactions per second")
+		maxMemoryMB    = flag.Int("max-memory", 512, "Maximum memory usage in MB")
+		cpuThreshold   = flag.Float64("cpu-threshold", 80.0, "CPU usage threshold percentage")
+	)
+	flag.Parse()
+
+	// Create output directory
+	if err := os.MkdirAll(*outputDir, 0755); err != nil {
+		log.Fatalf("Failed to create output directory: %v", err)
+	}
+
+	// Initialize performance auditor
+	auditor, err := internal.NewPerformanceAuditor(&internal.PerformanceAuditConfig{
+		TestType:       *testType,
+		Duration:       *duration,
+		OutputDir:      *outputDir,
+		Verbose:        *verbose,
+		Concurrent:     *concurrent,
+		LoadLevel:      *loadLevel,
+		ProfileEnabled: *profileEnabled,
+		BenchmarkMode:  *benchmarkMode,
+		StressTest:     *stressTest,
+		TargetTPS:      *targetTPS,
+		MaxMemoryMB:    *maxMemoryMB,
+		CPUThreshold:   *cpuThreshold,
+	})
+	if err != nil {
+		log.Fatalf("Failed to initialize performance auditor: %v", err)
+	}
+
+	ctx := context.Background()
+	ctx, cancel := context.WithTimeout(ctx, *duration+time.Minute) // Add buffer
+	defer cancel()
+
+	fmt.Printf("Starting performance audit: %s test for %v...\n", *testType, *duration)
+	if err := auditor.RunPerformanceTests(ctx); err != nil {
+		log.Fatalf("Performance audit failed: %v", err)
+	}
+
+	if err := auditor.GenerateReport(); err != nil {
+		log.Fatalf("Report generation failed: %v", err)
+	}
+
+	fmt.Printf("Performance audit complete. Reports saved to: %s\n", *outputDir)
+}