Add local production test environment setup

- docker-compose.local.yml: 本番Dockerfile使用・Traefikなし・ポート直接公開
- deploy_local.sh: ローカル環境のビルド・起動スクリプト
- sync_db.sh: サーバーDBダンプをローカルに取り込むスクリプト
- document/20_ローカルテスト環境.md: 手順ドキュメント

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.local.yml

@@ -0,0 +1,59 @@
+# ローカルでの本番同等テスト用
+# Traefikなし、ポート直接公開、本番用Dockerfileを使用
+# 使用: docker compose -f docker-compose.local.yml up -d
+
+services:
+  db:
+    image: postgis/postgis:16-3.4
+    container_name: keinasystem_db
+    environment:
+      POSTGRES_DB: keinasystem
+      POSTGRES_USER: keinasystem
+      POSTGRES_PASSWORD: ${DB_PASSWORD}
+    ports:
+      - "5432:5432"
+    volumes:
+      - postgres_data_local:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U keinasystem -d keinasystem"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  backend:
+    build:
+      context: ./backend
+      dockerfile: Dockerfile.prod
+    container_name: keinasystem_backend
+    environment:
+      DB_NAME: keinasystem
+      DB_USER: keinasystem
+      DB_PASSWORD: ${DB_PASSWORD}
+      DB_HOST: db
+      DB_PORT: 5432
+      SECRET_KEY: ${SECRET_KEY}
+      DEBUG: "False"
+      ALLOWED_HOSTS: localhost,127.0.0.1
+      CORS_ALLOWED_ORIGINS: http://localhost:3000
+      MAIL_API_KEY: ${MAIL_API_KEY}
+      FRONTEND_URL: http://localhost:3000
+    ports:
+      - "8000:8000"
+    depends_on:
+      db:
+        condition: service_healthy
+
+  frontend:
+    build:
+      context: ./frontend
+      dockerfile: Dockerfile.prod
+      args:
+        NEXT_PUBLIC_API_URL: http://localhost:8000
+    container_name: keinasystem_frontend
+    ports:
+      - "3000:3000"
+    depends_on:
+      - backend
+
+volumes:
+  postgres_data_local: