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.

tests/Unit/Application/GraphQL/GraphQLPlaygroundControllerTest.php

@@ -0,0 +1,108 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\Application\GraphQL;
+
+use App\Application\GraphQL\GraphQLPlaygroundController;
+use App\Framework\Config\Environment;
+use App\Framework\Config\EnvKey;
+use App\Framework\Http\Method;
+use App\Framework\Http\Request\HttpRequest;
+use App\Framework\Http\ServerEnvironment;
+use App\Framework\Router\Result\ViewResult;
+
+describe('GraphQLPlaygroundController', function () {
+    beforeEach(function () {
+        // Create test environment with array
+        $this->environment = new Environment([
+            'APP_DEBUG' => true,
+        ]);
+
+        // Mock HttpRequest
+        $this->createRequest = function (bool $isSecure = false, string $host = 'localhost') {
+            $serverEnv = new class($isSecure, $host) extends ServerEnvironment {
+                public function __construct(
+                    private bool $isSecure,
+                    private string $host
+                ) {
+                    parent::__construct([
+                        'HTTPS' => $isSecure ? 'on' : 'off',
+                        'HTTP_HOST' => $host,
+                        'SERVER_PROTOCOL' => 'HTTP/1.1',
+                        'REQUEST_METHOD' => 'GET',
+                        'REQUEST_URI' => '/graphql/playground',
+                    ]);
+                }
+
+                public function isSecure(): bool
+                {
+                    return $this->isSecure;
+                }
+
+                public function getHttpHost(): string
+                {
+                    return $this->host;
+                }
+            };
+
+            return new HttpRequest(
+                method: Method::GET,
+                uri: '/graphql/playground',
+                server: $serverEnv,
+                headers: new \App\Framework\Http\Headers([]),
+                cookies: new \App\Framework\Http\Cookies([]),
+                query: new \App\Framework\Http\QueryParameters([]),
+                parsedBody: null
+            );
+        };
+
+        $this->controller = new GraphQLPlaygroundController($this->environment);
+    });
+
+    it('returns playground view in development mode', function () {
+
+        $request = ($this->createRequest)();
+        $result = $this->controller->playground($request);
+
+        expect($result)->toBeInstanceOf(ViewResult::class);
+        expect($result->template)->toBe('graphql/playground');
+    });
+
+    it('includes GraphQL endpoints in view data', function () {
+        $request = ($this->createRequest)(isSecure: false, host: 'localhost');
+        $result = $this->controller->playground($request);
+
+        expect($result->data['graphql_endpoint'])->toBe('http://localhost/graphql');
+        expect($result->data['graphql_ws_endpoint'])->toBe('ws://localhost/graphql');
+        expect($result->data['graphql_schema_endpoint'])->toBe('http://localhost/graphql/schema');
+    });
+
+    it('uses HTTPS/WSS for secure connections', function () {
+        $request = ($this->createRequest)(isSecure: true, host: 'example.com');
+        $result = $this->controller->playground($request);
+
+        expect($result->data['graphql_endpoint'])->toBe('https://example.com/graphql');
+        expect($result->data['graphql_ws_endpoint'])->toBe('wss://example.com/graphql');
+        expect($result->data['graphql_schema_endpoint'])->toBe('https://example.com/graphql/schema');
+    });
+
+    it('throws exception when not in development mode', function () {
+        // Create production environment with APP_DEBUG=false
+        $prodEnvironment = new Environment(['APP_DEBUG' => false]);
+        $prodController = new GraphQLPlaygroundController($prodEnvironment);
+
+        $request = ($this->createRequest)();
+
+        expect(fn() => $prodController->playground($request))
+            ->toThrow(\RuntimeException::class, 'GraphQL Playground is only available in development mode');
+    });
+
+    it('works with different hostnames', function () {
+        $request = ($this->createRequest)(isSecure: true, host: 'api.example.com:8443');
+        $result = $this->controller->playground($request);
+
+        expect($result->data['graphql_endpoint'])->toBe('https://api.example.com:8443/graphql');
+        expect($result->data['graphql_ws_endpoint'])->toBe('wss://api.example.com:8443/graphql');
+    });
+});