文档对齐 React 技术栈，并支持渐进式数据库迁移

将 README 与部署文档从仅 init 改为 001 基线 + 增量迁移约定，并补充 create/status 脚手架与序号校验。

apps/backend/package.json

@@ -7,6 +7,8 @@
     "cleanup:dev-data": "tsx scripts/cleanup-dev-data.ts",
     "build": "tsc -p tsconfig.build.json && rm -rf dist/db/migrations && mkdir -p dist/db && cp -R src/db/migrations dist/db/migrations",
     "db:migrate": "tsx src/db/migrate.ts",
+    "db:migrate:create": "tsx scripts/create-migration.ts",
+    "db:migrate:status": "tsx scripts/migration-status.ts",
     "dev": "tsx watch --clear-screen=false src/index.ts",
     "format": "prettier --write .",
     "mock:claim": "tsx scripts/mock-kuaishou-cloud-claim.ts",