feat: User Components

[zigzagdev]

Motivation / 目的

This is the parent PR that brings the entire User feature epic from feat/user into main: user registration, authentication (login/logout/me), and full CRUD (find/update/delete), along with the bug fixes discovered while building each layer. Before this PR, main has no User resource at all.

本PRはUser機能一式（登録・認証・CRUD）をfeat/userからmainへ統合する親PRです。登録、認証(ログイン/ログアウト/me)、CRUD(検索/更新/削除)に加え、各層の実装中に見つかったバグ修正も含みます。現状mainにはUserリソースが存在しないため、これが導入のトリガーとなるPRです。

What I have done / 実施内容

User Domain & Registration

• UserEntity, AgeRange, Subscription/SubscriptionTier value objects, Email value object, users table migration (User Definition #399)
• POST /api/v1/user/create (User Registration API #400)

Authentication

• POST /api/v1/user/login — Sanctum token issuance (User LogIn #405)
• POST /api/v1/user/logout — token revocation (User Logout #408)
• GET /api/v1/user/me — fetch the authenticated user (feat: Add GET /v1/user/me endpoint to fetch the authenticated user / ログイン中ユーザー自身の情報を取得するAPIの追加 #542)

User CRUD

• GET /api/v1/users/{id} (User findById API #507)
• PATCH /api/v1/users/{id} (User Update API #500)
• DELETE /api/v1/users/{id} (User Delete API #514)

Bug fixes bundled in this branch

• CORS/Sanctum stateful domain configuration so the SPA can authenticate via cookies (Bug: マイページが表示されない (CORS supports_credentials=false + フロントポートのハードコード) / User mypage does not display after login #540)
• Made subscription_tier optional end-to-end (CreateUserCommand, CreateUserUseCase, and the Domain-layer factories), defaulting to free when omitted (Bug: POST /api/v1/user/create fails because subscription_tier is required / ユーザー作成APIがsubscription_tier必須のため失敗する #549)
• PATCH /api/v1/users/{id} now supports partial updates (previously required every field); UserController::updateUser now catches \Throwable instead of \Exception so \ValueError (e.g. invalid age_range) no longer leaks a raw debug page
• Removed a leftover dd() debug statement from UserController::createUser

Supporting infra

• Sanctum installation and configuration
• Codecov integration and mago static analysis CI

Test Results / テスト結果

• Domain/Application layer: Mockery-based unit tests for each UseCase, Command, Entity, and value object
• Infra layer: integration tests against the real test DB (heritage-mysql-test) for each repository method
• Presentation layer: integration tests for every endpoint (success and error responses)
• Full CI matrix (laravel 8.*/9.*/10.* × php 7.4/8.0/8.1/8.2), mago, and Codecov all passing

Closes #399, #400, #405, #408, #500, #507, #514, #540, #542, #549

[zigzagdev]

LGTM