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();
+        });
+    });
+});

tests/Unit/Framework/OutputBuffer/CapturedOutputTest.php

@@ -0,0 +1,169 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Framework\OutputBuffer\CapturedOutput;
+
+describe('CapturedOutput', function () {
+    it('stores content and result', function () {
+        $captured = new CapturedOutput(
+            content: "test output",
+            result: 42,
+            level: 1
+        );
+
+        expect($captured->content)->toBe("test output");
+        expect($captured->result)->toBe(42);
+        expect($captured->level)->toBe(1);
+    });
+
+    describe('isEmpty()', function () {
+        it('returns true for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->isEmpty())->toBeTrue();
+        });
+
+        it('returns true for whitespace-only content', function () {
+            $captured = new CapturedOutput("   \n\t  ", null, 1);
+            expect($captured->isEmpty())->toBeTrue();
+        });
+
+        it('returns false for non-empty content', function () {
+            $captured = new CapturedOutput("test", null, 1);
+            expect($captured->isEmpty())->toBeFalse();
+        });
+    });
+
+    describe('hasContent()', function () {
+        it('returns false for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->hasContent())->toBeFalse();
+        });
+
+        it('returns true for non-empty content', function () {
+            $captured = new CapturedOutput("test", null, 1);
+            expect($captured->hasContent())->toBeTrue();
+        });
+    });
+
+    describe('lines()', function () {
+        it('returns empty array for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->lines())->toBe([]);
+        });
+
+        it('splits content into lines', function () {
+            $captured = new CapturedOutput("Line 1\nLine 2\nLine 3", null, 1);
+            expect($captured->lines())->toBe(['Line 1', 'Line 2', 'Line 3']);
+        });
+
+        it('filters empty lines', function () {
+            $captured = new CapturedOutput("Line 1\n\nLine 2\n\n", null, 1);
+            expect($captured->lines())->toBe(['Line 1', 'Line 2']);
+        });
+
+        it('trims whitespace from lines', function () {
+            $captured = new CapturedOutput("  Line 1  \n  Line 2  ", null, 1);
+            expect($captured->lines())->toBe(['Line 1', 'Line 2']);
+        });
+    });
+
+    describe('lineCount()', function () {
+        it('returns 0 for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->lineCount())->toBe(0);
+        });
+
+        it('returns correct line count', function () {
+            $captured = new CapturedOutput("Line 1\nLine 2\nLine 3", null, 1);
+            expect($captured->lineCount())->toBe(3);
+        });
+
+        it('excludes empty lines from count', function () {
+            $captured = new CapturedOutput("Line 1\n\n\nLine 2", null, 1);
+            expect($captured->lineCount())->toBe(2);
+        });
+    });
+
+    describe('length()', function () {
+        it('returns 0 for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->length())->toBe(0);
+        });
+
+        it('returns byte length of content', function () {
+            $captured = new CapturedOutput("test", null, 1);
+            expect($captured->length())->toBe(4);
+        });
+
+        it('counts multibyte characters correctly', function () {
+            $captured = new CapturedOutput("café", null, 1);
+            expect($captured->length())->toBe(5); // UTF-8 encoding
+        });
+    });
+
+    describe('contains()', function () {
+        it('returns false for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->contains("test"))->toBeFalse();
+        });
+
+        it('returns true when content contains string', function () {
+            $captured = new CapturedOutput("Hello World", null, 1);
+            expect($captured->contains("World"))->toBeTrue();
+        });
+
+        it('returns false when content does not contain string', function () {
+            $captured = new CapturedOutput("Hello World", null, 1);
+            expect($captured->contains("Goodbye"))->toBeFalse();
+        });
+
+        it('is case-sensitive', function () {
+            $captured = new CapturedOutput("Hello World", null, 1);
+            expect($captured->contains("world"))->toBeFalse();
+        });
+    });
+
+    describe('trimmed()', function () {
+        it('returns empty string for empty content', function () {
+            $captured = new CapturedOutput("", null, 1);
+            expect($captured->trimmed())->toBe("");
+        });
+
+        it('trims whitespace from content', function () {
+            $captured = new CapturedOutput("  test  \n", null, 1);
+            expect($captured->trimmed())->toBe("test");
+        });
+
+        it('does not modify original content', function () {
+            $captured = new CapturedOutput("  test  ", null, 1);
+            $trimmed = $captured->trimmed();
+
+            expect($captured->content)->toBe("  test  ");
+            expect($trimmed)->toBe("test");
+        });
+    });
+
+    describe('result handling', function () {
+        it('stores null result', function () {
+            $captured = new CapturedOutput("test", null, 1);
+            expect($captured->result)->toBeNull();
+        });
+
+        it('stores scalar result', function () {
+            $captured = new CapturedOutput("test", 42, 1);
+            expect($captured->result)->toBe(42);
+        });
+
+        it('stores array result', function () {
+            $captured = new CapturedOutput("test", ['a' => 1], 1);
+            expect($captured->result)->toBe(['a' => 1]);
+        });
+
+        it('stores object result', function () {
+            $obj = new stdClass();
+            $captured = new CapturedOutput("test", $obj, 1);
+            expect($captured->result)->toBe($obj);
+        });
+    });
+});

tests/Unit/Framework/OutputBuffer/OutputBufferFlagsTest.php

@@ -0,0 +1,123 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Framework\OutputBuffer\OutputBufferFlag;
+use App\Framework\OutputBuffer\OutputBufferFlags;
+
+describe('OutputBufferFlags', function () {
+    describe('variadic constructor', function () {
+        it('accepts no flags', function () {
+            $flags = new OutputBufferFlags();
+            expect($flags->toBitmask())->toBe(0);
+        });
+
+        it('accepts single flag', function () {
+            $flags = new OutputBufferFlags(OutputBufferFlag::CLEANABLE);
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+        });
+
+        it('accepts multiple flags', function () {
+            $flags = new OutputBufferFlags(
+                OutputBufferFlag::CLEANABLE,
+                OutputBufferFlag::FLUSHABLE
+            );
+
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+            expect($flags->has(OutputBufferFlag::FLUSHABLE))->toBeTrue();
+        });
+    });
+
+    describe('factory methods', function () {
+        it('creates standard flags', function () {
+            $flags = OutputBufferFlags::standard();
+            expect($flags->has(OutputBufferFlag::STDFLAGS))->toBeTrue();
+        });
+
+        it('creates default flags', function () {
+            $flags = OutputBufferFlags::default();
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+        });
+
+        it('creates cleanable flags', function () {
+            $flags = OutputBufferFlags::cleanable();
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+        });
+
+        it('creates cleanable and flushable flags', function () {
+            $flags = OutputBufferFlags::cleanableAndFlushable();
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+            expect($flags->has(OutputBufferFlag::FLUSHABLE))->toBeTrue();
+        });
+    });
+
+    describe('toBitmask()', function () {
+        it('returns 0 for no flags', function () {
+            $flags = new OutputBufferFlags();
+            expect($flags->toBitmask())->toBe(0);
+        });
+
+        it('returns correct value for single flag', function () {
+            $flags = new OutputBufferFlags(OutputBufferFlag::CLEANABLE);
+            expect($flags->toBitmask())->toBe(PHP_OUTPUT_HANDLER_CLEANABLE);
+        });
+
+        it('combines multiple flags with OR', function () {
+            $flags = new OutputBufferFlags(
+                OutputBufferFlag::CLEANABLE,
+                OutputBufferFlag::FLUSHABLE
+            );
+
+            $expected = PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_FLUSHABLE;
+            expect($flags->toBitmask())->toBe($expected);
+        });
+
+        it('handles STDFLAGS correctly', function () {
+            $flags = new OutputBufferFlags(OutputBufferFlag::STDFLAGS);
+            expect($flags->toBitmask())->toBe(PHP_OUTPUT_HANDLER_STDFLAGS);
+        });
+    });
+
+    describe('has()', function () {
+        it('returns false when flag is not set', function () {
+            $flags = new OutputBufferFlags(OutputBufferFlag::CLEANABLE);
+            expect($flags->has(OutputBufferFlag::FLUSHABLE))->toBeFalse();
+        });
+
+        it('returns true when flag is set', function () {
+            $flags = new OutputBufferFlags(OutputBufferFlag::CLEANABLE);
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+        });
+
+        it('works with multiple flags', function () {
+            $flags = new OutputBufferFlags(
+                OutputBufferFlag::CLEANABLE,
+                OutputBufferFlag::FLUSHABLE,
+                OutputBufferFlag::REMOVABLE
+            );
+
+            expect($flags->has(OutputBufferFlag::CLEANABLE))->toBeTrue();
+            expect($flags->has(OutputBufferFlag::FLUSHABLE))->toBeTrue();
+            expect($flags->has(OutputBufferFlag::REMOVABLE))->toBeTrue();
+        });
+    });
+
+    describe('toArray()', function () {
+        it('returns empty array for no flags', function () {
+            $flags = new OutputBufferFlags();
+            expect($flags->toArray())->toBe([]);
+        });
+
+        it('returns all flags as array', function () {
+            $flags = new OutputBufferFlags(
+                OutputBufferFlag::CLEANABLE,
+                OutputBufferFlag::FLUSHABLE
+            );
+
+            $array = $flags->toArray();
+            expect($array)->toHaveCount(2);
+            expect($array)->toContain(OutputBufferFlag::CLEANABLE);
+            expect($array)->toContain(OutputBufferFlag::FLUSHABLE);
+        });
+    });
+});

tests/Unit/Framework/OutputBuffer/OutputBufferTest.php

@@ -0,0 +1,271 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Framework\OutputBuffer\OutputBuffer;
+use App\Framework\OutputBuffer\OutputBufferConfig;
+use App\Framework\OutputBuffer\OutputBufferException;
+use App\Framework\OutputBuffer\OutputBufferFlag;
+use App\Framework\OutputBuffer\OutputBufferFlags;
+use App\Framework\OutputBuffer\CapturedOutput;
+
+describe('OutputBuffer', function () {
+    beforeEach(function () {
+        // Ensure clean state
+        while (ob_get_level() > 0) {
+            ob_end_clean();
+        }
+    });
+
+    afterEach(function () {
+        // Cleanup after tests
+        while (ob_get_level() > 0) {
+            ob_end_clean();
+        }
+    });
+
+    describe('capture()', function () {
+        it('captures output from callback', function () {
+            $captured = OutputBuffer::capture(function () {
+                echo "Hello World";
+                return 42;
+            });
+
+            expect($captured)->toBeInstanceOf(CapturedOutput::class);
+            expect($captured->content)->toBe("Hello World");
+            expect($captured->result)->toBe(42);
+        });
+
+        it('captures empty output', function () {
+            $captured = OutputBuffer::capture(function () {
+                return "result";
+            });
+
+            expect($captured->content)->toBe("");
+            expect($captured->result)->toBe("result");
+            expect($captured->isEmpty())->toBeTrue();
+        });
+
+        it('captures multiline output', function () {
+            $captured = OutputBuffer::capture(function () {
+                echo "Line 1\n";
+                echo "Line 2\n";
+                echo "Line 3";
+            });
+
+            expect($captured->content)->toBe("Line 1\nLine 2\nLine 3");
+            expect($captured->lineCount())->toBe(3);
+            expect($captured->lines())->toBe(['Line 1', 'Line 2', 'Line 3']);
+        });
+
+        it('cleans up buffer on success', function () {
+            $levelBefore = ob_get_level();
+
+            OutputBuffer::capture(function () {
+                echo "test";
+            });
+
+            expect(ob_get_level())->toBe($levelBefore);
+        });
+
+        it('cleans up buffer on exception', function () {
+            $levelBefore = ob_get_level();
+
+            try {
+                OutputBuffer::capture(function () {
+                    echo "test";
+                    throw new RuntimeException('Test exception');
+                });
+            } catch (RuntimeException $e) {
+                // Expected exception
+            }
+
+            expect(ob_get_level())->toBe($levelBefore);
+        });
+
+        it('supports custom configuration', function () {
+            $callbackExecuted = false;
+
+            $config = OutputBufferConfig::withCallback(function (string $buffer) use (&$callbackExecuted) {
+                $callbackExecuted = true;
+                return strtoupper($buffer);
+            });
+
+            $captured = OutputBuffer::capture(function () {
+                echo "hello";
+            }, $config);
+
+            expect($callbackExecuted)->toBeTrue();
+            expect($captured->content)->toBe("HELLO");
+        });
+
+        it('handles nested captures', function () {
+            $captured1 = OutputBuffer::capture(function () {
+                echo "Outer Start\n";
+
+                $captured2 = OutputBuffer::capture(function () {
+                    echo "Inner";
+                    return "inner-result";
+                });
+
+                echo $captured2->content . " processed\n";
+                echo "Outer End";
+
+                return "outer-result";
+            });
+
+            expect($captured1->content)->toBe("Outer Start\nInner processed\nOuter End");
+            expect($captured1->result)->toBe("outer-result");
+        });
+    });
+
+    describe('start()', function () {
+        it('starts new buffer and returns handle', function () {
+            $levelBefore = ob_get_level();
+            $handle = OutputBuffer::start();
+
+            expect(ob_get_level())->toBe($levelBefore + 1);
+            expect($handle->level)->toBe($levelBefore + 1);
+            expect($handle->isActive())->toBeTrue();
+
+            $handle->end();
+        });
+
+        it('allows manual buffer management', function () {
+            $handle = OutputBuffer::start();
+
+            echo "Test output";
+            $content = $handle->clean();
+
+            expect($content)->toBe("Test output");
+            expect(ob_get_level())->toBe(0);
+        });
+
+        it('supports custom configuration', function () {
+            $config = OutputBufferConfig::forCapture();
+            $handle = OutputBuffer::start($config);
+
+            expect($handle->config)->toBe($config);
+
+            $handle->end();
+        });
+    });
+
+    describe('getCurrentLevel()', function () {
+        it('returns current buffer level', function () {
+            expect(OutputBuffer::getCurrentLevel())->toBe(0);
+
+            ob_start();
+            expect(OutputBuffer::getCurrentLevel())->toBe(1);
+
+            ob_start();
+            expect(OutputBuffer::getCurrentLevel())->toBe(2);
+
+            ob_end_clean();
+            ob_end_clean();
+        });
+    });
+
+    describe('isActive()', function () {
+        it('returns false when no buffers active', function () {
+            expect(OutputBuffer::isActive())->toBeFalse();
+        });
+
+        it('returns true when buffer is active', function () {
+            ob_start();
+            expect(OutputBuffer::isActive())->toBeTrue();
+            ob_end_clean();
+        });
+    });
+
+    describe('cleanAll()', function () {
+        it('cleans all active buffers', function () {
+            ob_start();
+            ob_start();
+            ob_start();
+
+            expect(ob_get_level())->toBe(3);
+
+            $count = OutputBuffer::cleanAll();
+
+            expect($count)->toBe(3);
+            expect(ob_get_level())->toBe(0);
+        });
+
+        it('returns 0 when no buffers active', function () {
+            $count = OutputBuffer::cleanAll();
+            expect($count)->toBe(0);
+        });
+    });
+
+    describe('getStatus()', function () {
+        it('returns status of all buffers', function () {
+            $status = OutputBuffer::getStatus();
+            expect($status)->toBeArray();
+        });
+
+        it('shows buffer information when active', function () {
+            ob_start();
+            $status = OutputBuffer::getStatus();
+
+            expect($status)->toBeArray();
+            expect($status)->toHaveCount(1);
+
+            ob_end_clean();
+        });
+    });
+
+    describe('withoutBuffering()', function () {
+        it('executes callback without buffering', function () {
+            $executedWithoutBuffer = false;
+
+            OutputBuffer::capture(function () use (&$executedWithoutBuffer) {
+                OutputBuffer::withoutBuffering(function () use (&$executedWithoutBuffer) {
+                    $executedWithoutBuffer = ob_get_level() === 0;
+                });
+            });
+
+            expect($executedWithoutBuffer)->toBeTrue();
+        });
+
+        it('restores buffers after callback', function () {
+            $captured = OutputBuffer::capture(function () {
+                echo "Before";
+
+                OutputBuffer::withoutBuffering(function () {
+                    // This output should not be captured
+                    echo "During";
+                });
+
+                echo "After";
+            });
+
+            expect($captured->content)->toBe("BeforeAfter");
+        });
+
+        it('returns callback result', function () {
+            $result = OutputBuffer::withoutBuffering(function () {
+                return 42;
+            });
+
+            expect($result)->toBe(42);
+        });
+    });
+
+    describe('exception handling', function () {
+        it('throws exception when capture fails', function () {
+            // This is hard to test as ob_start rarely fails
+            // but we test the exception exists
+            expect(OutputBufferException::failedToCapture())
+                ->toBeInstanceOf(OutputBufferException::class);
+        });
+
+        it('propagates callback exceptions', function () {
+            expect(function () {
+                OutputBuffer::capture(function () {
+                    throw new RuntimeException('Test');
+                });
+            })->toThrow(RuntimeException::class);
+        });
+    });
+});