Apply Composer changes: comprehensive API updates, migrations, middleware, and infrastructure improvements

- Add comprehensive database migrations (001-024) for schema evolution
- Enhance API schema with expanded type definitions and resolvers
- Add new middleware: audit logging, rate limiting, MFA enforcement, security, tenant auth
- Implement new services: AI optimization, billing, blockchain, compliance, marketplace
- Add adapter layer for cloud integrations (Cloudflare, Kubernetes, Proxmox, storage)
- Update Crossplane provider with enhanced VM management capabilities
- Add comprehensive test suite for API endpoints and services
- Update frontend components with improved GraphQL subscriptions and real-time updates
- Enhance security configurations and headers (CSP, CORS, etc.)
- Update documentation and configuration files
- Add new CI/CD workflows and validation scripts
- Implement design system improvements and UI enhancements

crossplane-provider-proxmox/pkg/controller/virtualmachine/backoff.go

@@ -0,0 +1,85 @@
+package virtualmachine
+
+import (
+	"time"
+)
+
+// ExponentialBackoff calculates the next retry delay using exponential backoff
+// Returns delays: 30s, 1m, 2m, 5m, 10m, then caps at 10m
+func ExponentialBackoff(attempt int) time.Duration {
+	delays := []time.Duration{
+		30 * time.Second,  // First retry: 30 seconds
+		1 * time.Minute,   // Second retry: 1 minute
+		2 * time.Minute,   // Third retry: 2 minutes
+		5 * time.Minute,   // Fourth retry: 5 minutes
+		10 * time.Minute,  // Fifth and subsequent retries: 10 minutes (capped)
+	}
+
+	if attempt < len(delays) {
+		return delays[attempt]
+	}
+	return delays[len(delays)-1] // Cap at maximum delay
+}
+
+// GetRequeueDelay calculates requeue delay based on error type and attempt count
+func GetRequeueDelay(err error, attemptCount int) time.Duration {
+	if err == nil {
+		return 30 * time.Second // Default for successful operations
+	}
+
+	errStr := err.Error()
+	
+	// Non-retryable errors (configuration issues)
+	if containsAny(errStr, []string{
+		"cannot get provider config",
+		"cannot get credentials",
+		"cannot find site",
+		"cannot create Proxmox client",
+	}) {
+		return 2 * time.Minute // Fixed delay for config errors
+	}
+
+	// Quota errors - longer delay
+	if containsAny(errStr, []string{
+		"quota exceeded",
+		"quota check failed",
+	}) {
+		return 5 * time.Minute
+	}
+
+	// VM creation failures - use exponential backoff
+	if containsAny(errStr, []string{
+		"cannot create VM",
+		"failed to import image",
+		"importdisk",
+		"not implemented",
+	}) {
+		return ExponentialBackoff(attemptCount)
+	}
+
+	// Node health issues
+	if containsAny(errStr, []string{
+		"node",
+		"unhealthy",
+		"not reachable",
+	}) {
+		return 2 * time.Minute
+	}
+
+	// Default: exponential backoff
+	return ExponentialBackoff(attemptCount)
+}
+
+func containsAny(s string, substrings []string) bool {
+	for _, substr := range substrings {
+		if len(s) >= len(substr) {
+			for i := 0; i <= len(s)-len(substr); i++ {
+				if s[i:i+len(substr)] == substr {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+