[Error Handling] Add comprehensive error handling, retries, and resilience patterns

[OneByJorah]

Error Handling Checklist

• Shell script error handling:
  • All scripts use set -euo pipefail
  • Add proper error handling with trap handlers
  • Add retry logic with exponential backoff for transient failures
  • Add timeout handling for external calls
  • Add proper cleanup on exit (trap EXIT)
  • Add structured error messages with context
• Docker health checks:
  • Improve health checks for all services (add proper endpoints)
  • Add startup probes (not just health checks)
  • Add readiness probes
  • Configure appropriate timeouts and retries
• Docker Compose resilience:
  • Add restart policies (already: unless-stopped)
  • Add depends_on with condition: service_healthy
  • Add resource limits (CPU, memory limits)
  • Add health check intervals/timeouts appropriate for each service
• Service-level resilience:
  • Add circuit breakers for external API calls
  • Add retry logic with exponential backoff for external calls
  • Add timeout configuration for all external calls
  • Add dead letter queue for failed operations
• Error monitoring:
  • Structured error logging with context
  • Error rate alerting
  • Dead man's switch for critical services
• Add error handling documentation to docs/ERROR_HANDLING.md