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/Framework/OutputBuffer/BufferHandleTest.php

@@ -0,0 +1,161 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Framework\OutputBuffer\BufferHandle;
+use App\Framework\OutputBuffer\OutputBuffer;
+use App\Framework\OutputBuffer\OutputBufferConfig;
+use App\Framework\OutputBuffer\OutputBufferException;
+
+describe('BufferHandle', function () {
+    beforeEach(function () {
+        while (ob_get_level() > 0) {
+            ob_end_clean();
+        }
+    });
+
+    afterEach(function () {
+        while (ob_get_level() > 0) {
+            ob_end_clean();
+        }
+    });
+
+    describe('clean()', function () {
+        it('cleans buffer and returns content', function () {
+            $handle = OutputBuffer::start();
+            echo "Test content";
+
+            $content = $handle->clean();
+
+            expect($content)->toBe("Test content");
+            expect(ob_get_level())->toBe(0);
+        });
+
+        it('throws exception if buffer level mismatch', function () {
+            $handle = OutputBuffer::start();
+            ob_start(); // Create additional buffer
+
+            expect(fn() => $handle->clean())
+                ->toThrow(OutputBufferException::class);
+
+            ob_end_clean();
+            $handle->end();
+        });
+    });
+
+    describe('end()', function () {
+        it('ends buffer without returning content', function () {
+            $handle = OutputBuffer::start();
+            echo "Test content";
+
+            $handle->end();
+
+            expect(ob_get_level())->toBe(0);
+        });
+
+        it('validates buffer level before ending', function () {
+            $handle = OutputBuffer::start();
+            $handle->end();
+
+            expect(fn() => $handle->end())
+                ->toThrow(OutputBufferException::class);
+        });
+    });
+
+    describe('flush()', function () {
+        it('flushes buffer contents', function () {
+            $handle = OutputBuffer::start();
+            echo "Test";
+
+            // Flush should work (though output goes nowhere in tests)
+            expect(fn() => $handle->flush())->not->toThrow(Exception::class);
+
+            $handle->end();
+        });
+    });
+
+    describe('getContents()', function () {
+        it('gets contents without clearing buffer', function () {
+            $handle = OutputBuffer::start();
+            echo "Test";
+
+            $content = $handle->getContents();
+
+            expect($content)->toBe("Test");
+            expect($handle->isActive())->toBeTrue();
+
+            $handle->end();
+        });
+
+        it('can be called multiple times', function () {
+            $handle = OutputBuffer::start();
+            echo "Test";
+
+            $content1 = $handle->getContents();
+            echo " More";
+            $content2 = $handle->getContents();
+
+            expect($content1)->toBe("Test");
+            expect($content2)->toBe("Test More");
+
+            $handle->end();
+        });
+    });
+
+    describe('getLength()', function () {
+        it('returns buffer content length', function () {
+            $handle = OutputBuffer::start();
+
+            expect($handle->getLength())->toBe(0);
+
+            echo "Test";
+            expect($handle->getLength())->toBe(4);
+
+            echo "ing";
+            expect($handle->getLength())->toBe(7);
+
+            $handle->end();
+        });
+    });
+
+    describe('isActive()', function () {
+        it('returns true when buffer is active', function () {
+            $handle = OutputBuffer::start();
+
+            expect($handle->isActive())->toBeTrue();
+
+            $handle->end();
+        });
+
+        it('returns false after buffer is cleaned', function () {
+            $handle = OutputBuffer::start();
+            $handle->end();
+
+            expect($handle->isActive())->toBeFalse();
+        });
+    });
+
+    describe('level validation', function () {
+        it('validates buffer level for all operations', function () {
+            $handle = OutputBuffer::start();
+            $handle->end();
+
+            // All operations should fail after buffer is ended
+            expect(fn() => $handle->clean())->toThrow(OutputBufferException::class);
+            expect(fn() => $handle->getContents())->toThrow(OutputBufferException::class);
+            expect(fn() => $handle->flush())->toThrow(OutputBufferException::class);
+        });
+
+        it('detects level mismatch', function () {
+            $handle1 = OutputBuffer::start();
+            $handle2 = OutputBuffer::start();
+
+            // Try to clean handle1 while handle2 is active
+            expect(fn() => $handle1->clean())
+                ->toThrow(OutputBufferException::class);
+
+            $handle2->end();
+            $handle1->end();
+        });
+    });
+});