fix: restore fork PR lint/format CI workflow (#9846)

## Problem

The lint/format CI workflow was broken for fork PRs in two ways:

### 1. Node version mismatch in setup-frontend action
The `setup-frontend` shared action (created in #8377) was missed when
Node version was standardized to `.nvmrc` in #9521. It still used
`node-version: 'lts/*'` instead of `node-version-file: '.nvmrc'`.

### 2. Fork PRs with lint issues silently passed CI
Fork PRs with auto-fixable lint/format issues got a **green checkmark**
despite having unfixed issues:
1. Auto-fix steps (`lint:fix`, `format`) fix issues in the workspace
2. `Commit changes` is correctly skipped for forks (can't push to fork
branches)
3. `Final validation` passes because it runs on the already-fixed
workspace
4. The `Comment on PR about manual fix needed` step tries to post a
comment via `actions/github-script`, but fork PRs have a read-only
`GITHUB_TOKEN` — the comment silently fails (`continue-on-error: true`)
5. **Result**: workflow reports success, contributor thinks their code
is clean

## Fix

- **setup-frontend**: Use `node-version-file: '.nvmrc'` instead of
`node-version: 'lts/*'`
- **ci-lint-format**: Replace the broken fork comment step with an
explicit `exit 1` that fails CI and prints clear fix instructions in the
log. This follows the principle from `.github/AGENTS.md`: fork PRs can't
post comments, so don't try.

## Testing
- [ ] Verify fork PRs with clean code still pass
- [ ] Verify fork PRs with lint issues now properly fail (instead of
silently passing)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9846-fix-restore-fork-PR-lint-format-CI-workflow-3226d73d3650811cb5bfe9f1f989cc0c)
by [Unito](https://www.unito.io)

.github/workflows/ci-lint-format.yaml

@@ -61,6 +61,22 @@ jobs:
           git commit -m "[automated] Apply ESLint and Oxfmt fixes"
           git push
 
+      - name: Fail for fork PRs with unfixed lint/format issues
+        if: steps.verify-changed-files.outputs.changed == 'true' && github.event.pull_request.head.repo.full_name != github.repository
+        run: |
+          echo "::error::Linting/formatting issues found. Since this PR is from a fork, auto-fix cannot be applied automatically."
+          echo ""
+          echo "Please run these commands locally and push the changes:"
+          echo "  pnpm lint:fix"
+          echo "  pnpm stylelint:fix"
+          echo "  pnpm format"
+          echo ""
+          echo "Or set up pre-commit hooks to automatically format on every commit:"
+          echo "  pnpm prepare"
+          echo ""
+          echo "See CONTRIBUTING.md for more details."
+          exit 1
+
       - name: Final validation
         run: |
           pnpm lint
@@ -84,16 +100,3 @@ jobs:
               repo: context.repo.repo,
               body: '## 🔧 Auto-fixes Applied\n\nThis PR has been automatically updated to fix linting and formatting issues.\n\n**⚠️ Important**: Your local branch is now behind. Run `git pull` before making additional changes to avoid conflicts.\n\n### Changes made:\n- ESLint auto-fixes\n- Oxfmt formatting'
             })
-
-      - name: Comment on PR about manual fix needed
-        if: steps.verify-changed-files.outputs.changed == 'true' && github.event.pull_request.head.repo.full_name != github.repository
-        continue-on-error: true
-        uses: actions/github-script@v8
-        with:
-          script: |
-            github.rest.issues.createComment({
-              issue_number: context.issue.number,
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: '## ⚠️ Linting/Formatting Issues Found\n\nThis PR has linting or formatting issues that need to be fixed.\n\n**Since this PR is from a fork, auto-fix cannot be applied automatically.**\n\n### Option 1: Set up pre-commit hooks (recommended)\nRun this once to automatically format code on every commit:\n```bash\npnpm prepare\n```\n\n### Option 2: Fix manually\nRun these commands and push the changes:\n```bash\npnpm lint:fix\npnpm format\n```\n\nSee [CONTRIBUTING.md](https://github.com/Comfy-Org/ComfyUI_frontend/blob/main/CONTRIBUTING.md#git-pre-commit-hooks) for more details.'
-            })