feat(Production): Complete production deployment infrastructure

- Add comprehensive health check system with multiple endpoints
- Add Prometheus metrics endpoint
- Add production logging configurations (5 strategies)
- Add complete deployment documentation suite:
  * QUICKSTART.md - 30-minute deployment guide
  * DEPLOYMENT_CHECKLIST.md - Printable verification checklist
  * DEPLOYMENT_WORKFLOW.md - Complete deployment lifecycle
  * PRODUCTION_DEPLOYMENT.md - Comprehensive technical reference
  * production-logging.md - Logging configuration guide
  * ANSIBLE_DEPLOYMENT.md - Infrastructure as Code automation
  * README.md - Navigation hub
  * DEPLOYMENT_SUMMARY.md - Executive summary
- Add deployment scripts and automation
- Add DEPLOYMENT_PLAN.md - Concrete plan for immediate deployment
- Update README with production-ready features

All production infrastructure is now complete and ready for deployment.

src/Framework/DI/Attributes/DefaultImplementation.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\DI\Attributes;
+
+use Attribute;
+
+/**
+ * Marks a class as the default implementation for an interface
+ *
+ * When applied to a class, this attribute enables automatic registration
+ * in the DI container with the specified interface (or auto-detected interface).
+ *
+ * Usage:
+ * - Explicit interface: #[DefaultImplementation(UserRepository::class)]
+ * - Auto-detect: #[DefaultImplementation] (uses first implemented interface)
+ *
+ * Validation:
+ * - If interface is specified: class must implement that interface
+ * - If interface is not specified: class must implement at least one interface
+ */
+#[Attribute(Attribute::TARGET_CLASS)]
+final readonly class DefaultImplementation
+{
+    /**
+     * @param class-string|null $interface Optional interface to bind to. If null, auto-detect first interface.
+     */
+    public function __construct(
+        public ?string $interface = null
+    ) {}
+}