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>

env/smoke.env

@@ -0,0 +1,18 @@
+# Smoke-test environment for local mev-bot startup
+# Replace RPC placeholders before connecting to live endpoints
+MEV_BOT_ENCRYPTION_KEY=smokestart_encryption_key_alpha_numeric_202410
+MEV_BOT_KEYSTORE_PATH=keystore/smoke
+MEV_BOT_AUDIT_LOG=logs/smoke_audit.log
+MEV_BOT_BACKUP_PATH=backups/smoke
+
+# Minimal network configuration
+ARBITRUM_RPC_ENDPOINT=wss://arb-sepolia.example/ws
+ARBITRUM_WS_ENDPOINT=wss://arb-sepolia.example/ws
+
+# Metrics/health
+METRICS_ENABLED=true
+METRICS_PORT=9090
+
+# Optional overrides for smoke run
+LOG_LEVEL=info
+LOG_FORMAT=text