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.

examples/default-implementation-usage.php

@@ -0,0 +1,334 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * DefaultImplementation Attribute - Real-World Usage Examples
+ *
+ * This file demonstrates practical usage of the #[DefaultImplementation] attribute
+ * in a typical application structure.
+ */
+
+namespace App\Examples\DefaultImplementation;
+
+use App\Framework\DI\Attributes\DefaultImplementation;
+
+// =============================================================================
+// Example 1: Repository Pattern
+// =============================================================================
+
+interface UserRepository
+{
+    public function findById(string $id): ?User;
+    public function findAll(): array;
+    public function save(User $user): void;
+}
+
+/**
+ * Database implementation of UserRepository
+ * Automatically registered as default implementation
+ */
+#[DefaultImplementation(UserRepository::class)]
+final readonly class DatabaseUserRepository implements UserRepository
+{
+    public function __construct(
+        private DatabaseConnection $db
+    ) {}
+
+    public function findById(string $id): ?User
+    {
+        // Database query implementation
+        return null; // Simplified
+    }
+
+    public function findAll(): array
+    {
+        return []; // Simplified
+    }
+
+    public function save(User $user): void
+    {
+        // Database insert/update implementation
+    }
+}
+
+// =============================================================================
+// Example 2: Service Layer
+// =============================================================================
+
+interface NotificationService
+{
+    public function send(string $recipient, string $message): void;
+}
+
+/**
+ * Email-based notification service
+ * Auto-detects NotificationService interface
+ */
+#[DefaultImplementation]  // No explicit interface - auto-detect
+final readonly class EmailNotificationService implements NotificationService
+{
+    public function __construct(
+        private MailerService $mailer
+    ) {}
+
+    public function send(string $recipient, string $message): void
+    {
+        $this->mailer->sendMail($recipient, 'Notification', $message);
+    }
+}
+
+// =============================================================================
+// Example 3: Infrastructure Adapters
+// =============================================================================
+
+interface CacheAdapter
+{
+    public function get(string $key): mixed;
+    public function set(string $key, mixed $value, int $ttl = 3600): void;
+    public function delete(string $key): void;
+}
+
+/**
+ * Redis cache adapter
+ * Automatically becomes the default cache implementation
+ */
+#[DefaultImplementation(CacheAdapter::class)]
+final readonly class RedisCacheAdapter implements CacheAdapter
+{
+    public function __construct(
+        private RedisConnection $redis
+    ) {}
+
+    public function get(string $key): mixed
+    {
+        return $this->redis->get($key);
+    }
+
+    public function set(string $key, mixed $value, int $ttl = 3600): void
+    {
+        $this->redis->setex($key, $ttl, $value);
+    }
+
+    public function delete(string $key): void
+    {
+        $this->redis->del($key);
+    }
+}
+
+// =============================================================================
+// Example 4: HTTP Client Abstraction
+// =============================================================================
+
+interface HttpClient
+{
+    public function get(string $url, array $headers = []): HttpResponse;
+    public function post(string $url, array $data, array $headers = []): HttpResponse;
+}
+
+/**
+ * Guzzle-based HTTP client
+ * Auto-detects HttpClient interface
+ */
+#[DefaultImplementation]
+final readonly class GuzzleHttpClient implements HttpClient
+{
+    public function __construct(
+        private \GuzzleHttp\Client $guzzle
+    ) {}
+
+    public function get(string $url, array $headers = []): HttpResponse
+    {
+        $response = $this->guzzle->get($url, ['headers' => $headers]);
+        return new HttpResponse($response->getStatusCode(), (string) $response->getBody());
+    }
+
+    public function post(string $url, array $data, array $headers = []): HttpResponse
+    {
+        $response = $this->guzzle->post($url, [
+            'headers' => $headers,
+            'json' => $data
+        ]);
+        return new HttpResponse($response->getStatusCode(), (string) $response->getBody());
+    }
+}
+
+// =============================================================================
+// Example 5: Multiple Interfaces (Auto-detect First)
+// =============================================================================
+
+interface EventLogger
+{
+    public function logEvent(string $event, array $context): void;
+}
+
+interface Flushable
+{
+    public function flush(): void;
+}
+
+/**
+ * File-based event logger with flush capability
+ * Auto-detects EventLogger (first interface)
+ */
+#[DefaultImplementation]  // Binds to EventLogger, not Flushable
+final readonly class FileEventLogger implements EventLogger, Flushable
+{
+    public function __construct(
+        private string $logFilePath
+    ) {}
+
+    public function logEvent(string $event, array $context): void
+    {
+        file_put_contents(
+            $this->logFilePath,
+            json_encode(['event' => $event, 'context' => $context]) . "\n",
+            FILE_APPEND
+        );
+    }
+
+    public function flush(): void
+    {
+        file_put_contents($this->logFilePath, '');
+    }
+}
+
+// =============================================================================
+// Example 6: Using Default Implementations
+// =============================================================================
+
+/**
+ * Service that depends on default implementations
+ */
+final readonly class UserService
+{
+    public function __construct(
+        private UserRepository $userRepository,         // DatabaseUserRepository injected
+        private NotificationService $notifications,     // EmailNotificationService injected
+        private CacheAdapter $cache                     // RedisCacheAdapter injected
+    ) {}
+
+    public function registerUser(string $email, string $name): void
+    {
+        // Check cache first
+        $cachedUser = $this->cache->get("user:$email");
+        if ($cachedUser !== null) {
+            return; // User already registered
+        }
+
+        // Create and save user
+        $user = new User($email, $name);
+        $this->userRepository->save($user);
+
+        // Cache the user
+        $this->cache->set("user:$email", $user, 3600);
+
+        // Send notification
+        $this->notifications->send($email, "Welcome to our platform, $name!");
+    }
+}
+
+// =============================================================================
+// Example 7: Advanced - Combining with Initializers
+// =============================================================================
+
+interface PaymentGateway
+{
+    public function charge(int $amountInCents, string $token): PaymentResult;
+}
+
+/**
+ * Stripe payment gateway
+ * Requires complex initialization via Initializer
+ */
+#[DefaultImplementation(PaymentGateway::class)]
+final readonly class StripePaymentGateway implements PaymentGateway
+{
+    public function __construct(
+        private StripeApiClient $stripeClient
+    ) {}
+
+    public function charge(int $amountInCents, string $token): PaymentResult
+    {
+        return $this->stripeClient->createCharge($amountInCents, $token);
+    }
+}
+
+/**
+ * Initializer for StripeApiClient
+ * Runs after DefaultImplementation registration
+ */
+final readonly class StripeInitializer
+{
+    #[\App\Framework\DI\Initializer]
+    public function initializeStripeClient(): StripeApiClient
+    {
+        $apiKey = $_ENV['STRIPE_SECRET_KEY'] ?? throw new \RuntimeException('Missing Stripe API key');
+
+        return new StripeApiClient($apiKey, [
+            'api_version' => '2023-10-16',
+            'timeout' => 30
+        ]);
+    }
+}
+
+// =============================================================================
+// Usage in Application
+// =============================================================================
+
+/**
+ * The container automatically resolves all dependencies:
+ *
+ * $container->get(UserService::class)
+ *   -> UserRepository (DatabaseUserRepository)
+ *   -> NotificationService (EmailNotificationService)
+ *   -> CacheAdapter (RedisCacheAdapter)
+ *
+ * All instances are singletons - same instance returned on subsequent calls
+ */
+
+// =============================================================================
+// Stub Classes (for example completeness)
+// =============================================================================
+
+class User
+{
+    public function __construct(
+        public string $email,
+        public string $name
+    ) {}
+}
+
+class DatabaseConnection {}
+class MailerService
+{
+    public function sendMail(string $to, string $subject, string $body): void {}
+}
+class RedisConnection
+{
+    public function get(string $key): mixed { return null; }
+    public function setex(string $key, int $ttl, mixed $value): void {}
+    public function del(string $key): void {}
+}
+class HttpResponse
+{
+    public function __construct(
+        public int $statusCode,
+        public string $body
+    ) {}
+}
+class StripeApiClient
+{
+    public function __construct(string $apiKey, array $options) {}
+    public function createCharge(int $amount, string $token): PaymentResult
+    {
+        return new PaymentResult(true, 'ch_123');
+    }
+}
+class PaymentResult
+{
+    public function __construct(
+        public bool $success,
+        public string $transactionId
+    ) {}
+}