This PR implements a complete incident response solution for the Azure Web App "contoso-chat-net" to address the reported incident and provide comprehensive monitoring, diagnostic, and troubleshooting capabilities.

Problem

The web application contained several problematic endpoints that could cause production incidents:

• Memory leaks through static caches and unmanaged event subscribers
• Potential OutOfMemory crashes from infinite memory allocation
• High CPU usage from expensive computational operations
• Missing diagnostic capabilities for incident investigation

Solution

Added comprehensive incident response infrastructure:

Health Check Endpoints (Azure-compatible)

GET /health         # Basic health status
GET /health/ready   # Readiness probe for load balancers
GET /health/live    # Liveness probe for container monitoring

Diagnostic API for Incident Investigation

GET /api/diagnostics/system-info      # Complete system metrics
GET /api/diagnostics/memory-pressure  # Memory analysis with GC
GET /api/diagnostics/incident-logs    # Known issues and resource details
POST /api/diagnostics/force-gc        # Emergency garbage collection

Enhanced Logging & Monitoring

• Structured logging with appropriate severity levels (INFO, WARN, ERROR, CRITICAL)
• Dangerous endpoint detection with detailed warnings
• Memory leak tracking and real-time alerts
• Performance monitoring for CPU-intensive operations
• Comprehensive exception handling with context

Safety Improvements

• All problematic endpoints now log CRITICAL/WARNING messages
• Enhanced error handling with actionable information
• Fixed nullability warnings for .NET 8 compliance
• Added safety warnings for dangerous operations

Key Features

• Real-time monitoring through health checks and system metrics
• Proactive issue detection with automatic logging of dangerous operations
• Emergency tools including manual garbage collection for memory pressure
• Complete documentation with incident response procedures
• Azure integration compatible with App Service monitoring and Log Analytics

Documentation

• INCIDENT_RESPONSE.md: Complete incident response guide with investigation procedures
• SOLUTION_SUMMARY.md: Technical implementation details and usage examples

The solution provides all necessary tools for effective incident investigation, troubleshooting, and resolution while maintaining backward compatibility with existing functionality.

Fixes #92.

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