feat: implement User registration API / ユーザー登録APIの実装

[zigzagdev]

Motivation

The application needed a full vertical slice for user registration, from the database layer up to the HTTP endpoint. This PR implements the complete User registration feature across all layers — domain, infrastructure, application, and presentation — along with test coverage and Codecov integration.

What I have done

Domain layer

• Added users table migration and User Eloquent model
• Added AgeRange enum, SubscriptionTier enum, Subscription value object, and UserEntity
• Added SubscriptionFactory and UserEntityFactory

Infrastructure layer

• Added UserRepositoryInterface and UserRepository (maps CreateUserCommand to DB columns, uses wasRecentlyCreated to detect insert failures)
• Added UserDto with typed public readonly properties
• Added UserDtoFactory to build UserDto from a raw attribute array

Application layer

• Added CreateUserCommand with required key validation (first_name, last_name, email, password, age_range, subscription_tier)
• Added CreateUserUseCase delegating to UserRepositoryInterface

Presentation layer

• Added UserViewModel and UserViewModelFactory
• Added UserController with try/catch: returns 201 on success, 500 to client + Log::error on failure
• Registered POST /api/v1/user/create route
• Bound UserRepositroyInterface → UserRepository in RepositoryProvider

CI / Coverage

• Added pcov to the CI workflow and configured PHPUnit to generate Clover XML
• Integrated codecov/codecov-action@v5 for per-PR coverage reporting
• Added codecov.yml (80% patch coverage threshold)

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モチベーション

ユーザー登録機能をDBからHTTPエンドポイントまで縦断的に実装する必要がありました。このPRはドメイン・インフラ・アプリケーション・プレゼンテーションの全層にわたってユーザー登録機能を実装し、テストカバレッジとCodecov連携も合わせて導入します。

実装内容

ドメイン層

• users テーブルのマイグレーションと User Eloquentモデルを追加
• AgeRange enum・SubscriptionTier enum・Subscription 値オブジェクト・UserEntity を追加
• SubscriptionFactory・UserEntityFactory を追加

インフラ層

• UserRepositoryInterface と UserRepository を追加（CreateUserCommand をDBカラムにマッピング、wasRecentlyCreated で挿入失敗を検出）
• UserDto を追加（型付き public readonly プロパティ）
• UserDtoFactory を追加（生配列から UserDto を生成）

アプリケーション層

• CreateUserCommand を追加（必須キーのバリデーション：first_name・last_name・email・password・age_range・subscription_tier）
• CreateUserUseCase を追加（UserRepositoryInterface に委譲）

プレゼンテーション層

• UserViewModel と UserViewModelFactory を追加
• UserController を追加（try/catch：成功時201、失敗時クライアントに500 + Log::error で詳細を記録）
• POST /api/v1/user/create ルートを登録
• RepositoryProvider に UserRepositroyInterface → UserRepository のバインドを追加

CI / カバレッジ

• CIワークフローに pcov を追加し、PHPUnitがClover XMLを生成するよう設定
• codecov/codecov-action@v5 を追加してPRごとにカバレッジを報告
• codecov.yml を追加（patchカバレッジ閾値80%）

Test Results

PASS  Tests\Unit\Packages\Domains\UserRepositoryTest
✓ create user returns user dto on success
✓ create user throws exception when insert fails

PASS  App\Packages\Features\Tests\CreateUserTest
✓ create user returns 201 with user data
✓ create user returns 500 when required key is missing
✓ create user returns 500 on duplicate email

Tests: 5 passed (18 assertions)

[codecov]

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