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>

monitoring/alerts.yml

@@ -0,0 +1,21 @@
+groups:
+  - name: mev-bot-alerts
+    interval: 30s
+    rules:
+      - alert: MEVBotHighErrorRate
+        expr: mev_bot_trade_error_rate > 0.25
+        for: 10m
+        labels:
+          severity: critical
+        annotations:
+          summary: "MEV bot trade error rate is above 25%"
+          description: "Error rate has exceeded 25% for 10 minutes. Investigate RPC stability, pool state, and contract execution failures."
+
+      - alert: MEVBotDegradedProfitFactor
+        expr: mev_bot_profit_factor < 1
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          summary: "MEV bot profit factor dropped below 1"
+          description: "Profit factor is below 1 for 15 minutes, indicating unprofitable execution after gas costs. Review recent opportunities and gas settings."

monitoring/prometheus.yml

@@ -7,8 +7,7 @@ global:
     monitor: 'mev-bot-monitor'
 
 rule_files:
-  # - "first_rules.yml"
-  # - "second_rules.yml"
+  - "alerts.yml"
 
 scrape_configs:
   - job_name: 'mev-bot'
@@ -47,4 +46,4 @@ alerting:
 #    write_relabel_configs:
 #      - source_labels: [__name__]
 #        regex: 'mev_bot_.*'
-#        action: keep
+#        action: keep