Fix PR Check workflow initialization for local setup action

[Copilot]

The PR Check workflow invoked the local setup-node-env action before the repository was checked out, causing job initialization to fail with Can't find 'action.yml'. This updates the workflow so each job resolves the local action from a checked-out workspace while preserving existing check behavior.

• Workflow ordering

  • Add actions/checkout@v4 before every use of ./.github/actions/setup-node-env
  • Keep the rest of each job’s validation steps unchanged

• Build validation checkout depth

  • Move full-history checkout to the build-validation job with fetch-depth: 0
  • Remove the misplaced fetch-depth input from the local action invocation

• Composite action scope

  • Narrow .github/actions/setup-node-env to Node setup + npm ci
  • Leave checkout responsibility to the calling workflow to avoid redundant clones across jobs

• Workflow hardening

  • Add minimal contents: read permissions
  • Only run the optional Crowdin download when the token is available

steps:
  - name: Checkout repository
    uses: actions/checkout@v4

  - name: Setup Node environment
    uses: ./.github/actions/setup-node-env