BE: Optimize performance and add comprehensive testing and monitoring for warn mode

Why are we doing this work

This backend implementation focuses on performance optimization, comprehensive testing, and monitoring for the warn mode functionality. As warn mode introduces additional database queries for dismissals and policy violation tracking, proper optimization and monitoring are essential to maintain system performance and reliability.

This ensures the warn mode feature is production-ready with proper observability and performance characteristics.

Relevant links

• Epic: &15552
• Related issue: #549766 (closed)
• All previous implementation dependencies: #561885 (closed), #561886 (closed), #561887 (closed), #561888 (closed), #561889 (closed)

Implementation

• Implement performance optimizations for policy-filtered vulnerability queries
• Add database indexes for efficient dismissal and violation lookups
• Create comprehensive test coverage for dismissal workflows and edge cases
• Add API documentation for new dismissal endpoints and parameters
• Implement integration tests for policy lifecycle and dismissal persistence
• Create monitoring and metrics for warn mode policy usage and performance
• Add performance benchmarks for dismissal-related database operations
• Implement caching strategies for frequently accessed policy violation data

Technical notes

• Database query optimization for dismissal joins and policy violation filtering
• Proper indexing strategy for security_finding_policy_dismissals table
• Comprehensive test coverage including edge cases like policy recreation
• API documentation for GraphQL mutations and new endpoints
• Integration tests covering full dismissal workflow from UI to database
• Monitoring dashboards for warn mode adoption and performance metrics
• Performance testing for high-volume dismissal scenarios
• Caching implementation for policy violation status queries
• Load testing for mixed warn/enforce policy scenarios

Validation Steps

• Database queries for dismissal operations perform within acceptable SLA targets
• Comprehensive test suite covers all dismissal workflows and edge cases
• API documentation accurately reflects new dismissal functionality
• Integration tests validate end-to-end dismissal persistence across policy changes
• Monitoring dashboards provide visibility into warn mode usage and performance
• Performance benchmarks demonstrate acceptable response times under load
• Caching strategies effectively reduce database load for frequent queries
• Load testing validates system stability with high dismissal volumes
• All existing functionality maintains performance characteristics