fix(be): upgrade node to v22 to use esmodule in nestjs

[dotoleeoak]

Description

#2677 에서 graphql-upload를 v17로 업그레이드하였는데, pure-esm만 지원하는 모듈로 현재 x86 환경에서 아래와 같은 에러가 발생합니다. NestJS는 pure-esm을 지원하지 않아 발생하는 문제입니다. (관련 이슈: nestjs/nest#8736)

/app/dist/apps/admin/main.js:171735
    app.use((0, _graphqlUploadExpress.default)({
                                              ^

TypeError: (0 , _graphqlUploadExpress.default) is not a function
    at bootstrap (/app/dist/apps/admin/main.js:171735:47)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

Node.js v22.12.0에 도입된 require(esm) 지원을 적용합니다.
nodejs/node#55085

Additional context

Node.js 버전을 더 분명히 하도록 .nvmrc와 package.json의 engines 필드를 추가하였습니다.

---

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines
• Read the Contributing Guidelines and follow the Commit Convention
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[Copilot]

Copilot reviewed 2 out of 7 changed files in this pull request and generated no comments.

Files not reviewed (5)

• .devcontainer/Dockerfile: Language not supported
• .gitpod.Dockerfile: Language not supported
• .nvmrc: Language not supported
• apps/backend/Dockerfile: Language not supported
• package.json: Language not supported

Comments suppressed due to low confidence (1)

.github/workflows/ci.yml:264

• The smoke test instructions are currently only in comments; consider implementing an actual smoke test to verify backend health automatically.

# TODO: write smoke test for backend

[jspark2000]

LGTM 👍🏼