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/Domain/SmartLink/Services/SmartLinkServiceTest.php

@@ -0,0 +1,395 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Domain\SmartLink\Enums\LinkStatus;
+use App\Domain\SmartLink\Enums\LinkType;
+use App\Domain\SmartLink\Enums\ServiceType;
+use App\Domain\SmartLink\Exceptions\ShortCodeAlreadyExistsException;
+use App\Domain\SmartLink\Exceptions\SmartLinkNotFoundException;
+use App\Domain\SmartLink\Services\ShortCodeGenerator;
+use App\Domain\SmartLink\Services\SmartLinkService;
+use App\Domain\SmartLink\ValueObjects\DestinationUrl;
+use App\Domain\SmartLink\ValueObjects\LinkTitle;
+use App\Domain\SmartLink\ValueObjects\ShortCode;
+use App\Domain\SmartLink\ValueObjects\SmartLinkId;
+use App\Framework\DateTime\SystemClock;
+use Tests\Support\InMemoryLinkDestinationRepository;
+use Tests\Support\InMemorySmartLinkRepository;
+
+describe('SmartLinkService', function () {
+    beforeEach(function () {
+        $this->clock = new SystemClock();
+        $this->linkRepository = new InMemorySmartLinkRepository();
+        $this->destinationRepository = new InMemoryLinkDestinationRepository();
+        $this->shortCodeGenerator = new ShortCodeGenerator($this->linkRepository);
+
+        $this->service = new SmartLinkService(
+            linkRepository: $this->linkRepository,
+            destinationRepository: $this->destinationRepository,
+            shortCodeGenerator: $this->shortCodeGenerator,
+            clock: $this->clock
+        );
+    });
+
+    describe('createLink', function () {
+        it('creates link with auto-generated short code', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            expect($link->type)->toBe(LinkType::RELEASE);
+            expect($link->title->toString())->toBe('My Album');
+            expect($link->status)->toBe(LinkStatus::DRAFT);
+            expect($link->userId)->toBeNull();
+        });
+
+        it('creates link with custom short code', function () {
+            $customCode = ShortCode::fromString('custom');
+
+            $link = $this->service->createLink(
+                type: LinkType::BIO_LINK,
+                title: LinkTitle::fromString('My Bio'),
+                customShortCode: $customCode
+            );
+
+            expect($link->shortCode->equals($customCode))->toBeTrue();
+        });
+
+        it('creates link with user ID', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album'),
+                userId: 'user123'
+            );
+
+            expect($link->userId)->toBe('user123');
+            expect($link->isOwnedBy('user123'))->toBeTrue();
+        });
+
+        it('creates link with cover image', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album'),
+                coverImageUrl: 'https://example.com/cover.jpg'
+            );
+
+            expect($link->coverImageUrl)->toBe('https://example.com/cover.jpg');
+        });
+
+        it('throws exception when custom short code already exists', function () {
+            $shortCode = ShortCode::fromString('exist1');
+
+            $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('First'),
+                customShortCode: $shortCode
+            );
+
+            expect(fn() => $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Second'),
+                customShortCode: $shortCode
+            ))->toThrow(ShortCodeAlreadyExistsException::class);
+        });
+
+        it('persists link to repository', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $foundLink = $this->linkRepository->findById($link->id);
+            expect($foundLink)->toBeInstanceOf(\App\Domain\SmartLink\Entities\SmartLink::class);
+            expect($foundLink->id->equals($link->id))->toBeTrue();
+        });
+    });
+
+    describe('findById', function () {
+        it('finds existing link by ID', function () {
+            $createdLink = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $foundLink = $this->service->findById($createdLink->id);
+
+            expect($foundLink->id->equals($createdLink->id))->toBeTrue();
+            expect($foundLink->title->toString())->toBe('My Album');
+        });
+
+        it('throws exception when link not found', function () {
+            $nonExistentId = SmartLinkId::generate($this->clock);
+
+            expect(fn() => $this->service->findById($nonExistentId))
+                ->toThrow(SmartLinkNotFoundException::class);
+        });
+    });
+
+    describe('findByShortCode', function () {
+        it('finds existing link by short code', function () {
+            $shortCode = ShortCode::fromString('abc123');
+
+            $createdLink = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album'),
+                customShortCode: $shortCode
+            );
+
+            $foundLink = $this->service->findByShortCode($shortCode);
+
+            expect($foundLink->id->equals($createdLink->id))->toBeTrue();
+            expect($foundLink->shortCode->equals($shortCode))->toBeTrue();
+        });
+
+        it('throws exception when short code not found', function () {
+            $nonExistentCode = ShortCode::fromString('notfound');
+
+            expect(fn() => $this->service->findByShortCode($nonExistentCode))
+                ->toThrow(SmartLinkNotFoundException::class);
+        });
+
+        it('is case-insensitive for short code lookup', function () {
+            $shortCode = ShortCode::fromString('AbCdEf');
+
+            $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album'),
+                customShortCode: $shortCode
+            );
+
+            $lowerCaseCode = ShortCode::fromString('abcdef');
+            $foundLink = $this->service->findByShortCode($lowerCaseCode);
+
+            expect($foundLink)->toBeInstanceOf(\App\Domain\SmartLink\Entities\SmartLink::class);
+            expect($foundLink->shortCode->toString())->toBe('AbCdEf');
+        });
+    });
+
+    describe('updateTitle', function () {
+        it('updates link title', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Original Title')
+            );
+
+            $newTitle = LinkTitle::fromString('Updated Title');
+            $updatedLink = $this->service->updateTitle($link->id, $newTitle);
+
+            expect($updatedLink->title->toString())->toBe('Updated Title');
+            expect($updatedLink->id->equals($link->id))->toBeTrue();
+        });
+
+        it('persists title update', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Original Title')
+            );
+
+            $newTitle = LinkTitle::fromString('Updated Title');
+            $this->service->updateTitle($link->id, $newTitle);
+
+            $foundLink = $this->service->findById($link->id);
+            expect($foundLink->title->toString())->toBe('Updated Title');
+        });
+    });
+
+    describe('publishLink', function () {
+        it('publishes draft link', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            expect($link->status)->toBe(LinkStatus::DRAFT);
+
+            $publishedLink = $this->service->publishLink($link->id);
+
+            expect($publishedLink->status)->toBe(LinkStatus::ACTIVE);
+            expect($publishedLink->isActive())->toBeTrue();
+        });
+
+        it('persists published status', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $this->service->publishLink($link->id);
+
+            $foundLink = $this->service->findById($link->id);
+            expect($foundLink->status)->toBe(LinkStatus::ACTIVE);
+        });
+    });
+
+    describe('pauseLink', function () {
+        it('pauses active link', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $publishedLink = $this->service->publishLink($link->id);
+            expect($publishedLink->status)->toBe(LinkStatus::ACTIVE);
+
+            $pausedLink = $this->service->pauseLink($link->id);
+            expect($pausedLink->status)->toBe(LinkStatus::PAUSED);
+        });
+    });
+
+    describe('addDestination', function () {
+        it('adds destination to link', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $destination = $this->service->addDestination(
+                linkId: $link->id,
+                serviceType: ServiceType::SPOTIFY,
+                url: DestinationUrl::fromString('https://open.spotify.com/album/123')
+            );
+
+            expect($destination->linkId->equals($link->id))->toBeTrue();
+            expect($destination->serviceType)->toBe(ServiceType::SPOTIFY);
+            expect($destination->url->toString())->toBe('https://open.spotify.com/album/123');
+        });
+
+        it('adds destination with priority', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $destination = $this->service->addDestination(
+                linkId: $link->id,
+                serviceType: ServiceType::SPOTIFY,
+                url: DestinationUrl::fromString('https://open.spotify.com/album/123'),
+                priority: 10
+            );
+
+            expect($destination->priority)->toBe(10);
+        });
+
+        it('adds default destination', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $destination = $this->service->addDestination(
+                linkId: $link->id,
+                serviceType: ServiceType::SPOTIFY,
+                url: DestinationUrl::fromString('https://open.spotify.com/album/123'),
+                isDefault: true
+            );
+
+            expect($destination->isDefault)->toBeTrue();
+        });
+    });
+
+    describe('getDestinations', function () {
+        it('retrieves all destinations for link', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $this->service->addDestination(
+                linkId: $link->id,
+                serviceType: ServiceType::SPOTIFY,
+                url: DestinationUrl::fromString('https://spotify.com/album/1')
+            );
+
+            $this->service->addDestination(
+                linkId: $link->id,
+                serviceType: ServiceType::APPLE_MUSIC,
+                url: DestinationUrl::fromString('https://music.apple.com/album/1')
+            );
+
+            $destinations = $this->service->getDestinations($link->id);
+
+            expect($destinations)->toHaveCount(2);
+        });
+
+        it('returns empty array when no destinations', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $destinations = $this->service->getDestinations($link->id);
+
+            expect($destinations)->toBeEmpty();
+        });
+    });
+
+    describe('deleteLink', function () {
+        it('deletes link from repository', function () {
+            $link = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('My Album')
+            );
+
+            $this->service->deleteLink($link->id);
+
+            expect(fn() => $this->service->findById($link->id))
+                ->toThrow(SmartLinkNotFoundException::class);
+        });
+    });
+
+    describe('getUserLinks', function () {
+        it('retrieves all links for user', function () {
+            $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Album 1'),
+                userId: 'user123'
+            );
+
+            $this->service->createLink(
+                type: LinkType::BIO_LINK,
+                title: LinkTitle::fromString('Bio'),
+                userId: 'user123'
+            );
+
+            $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Album 2'),
+                userId: 'user456'
+            );
+
+            $userLinks = $this->service->getUserLinks('user123');
+
+            expect($userLinks)->toHaveCount(2);
+        });
+
+        it('filters links by status', function () {
+            $link1 = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Album 1'),
+                userId: 'user123'
+            );
+
+            $link2 = $this->service->createLink(
+                type: LinkType::RELEASE,
+                title: LinkTitle::fromString('Album 2'),
+                userId: 'user123'
+            );
+
+            $this->service->publishLink($link2->id);
+
+            $draftLinks = $this->service->getUserLinks('user123', LinkStatus::DRAFT);
+            $activeLinks = $this->service->getUserLinks('user123', LinkStatus::ACTIVE);
+
+            expect($draftLinks)->toHaveCount(1);
+            expect($activeLinks)->toHaveCount(1);
+        });
+
+        it('returns empty array when user has no links', function () {
+            $userLinks = $this->service->getUserLinks('nonexistent');
+
+            expect($userLinks)->toBeEmpty();
+        });
+    });
+});