fix(release): align nightly workflow with release patterns

Refactors the release-nightly.yml workflow to follow the established pattern used by other release workflows (release-manual, release-patch, etc.).

This change introduces a dedicated release subdirectory for the checkout, ensuring that all subsequent steps and local composite actions operate on a consistent and specific version of the code. This resolves an issue where the workflow could inadvertently execute stale or incorrect versions of actions from the default branch.

.github/workflows/release-nightly.yml

@@ -30,29 +30,33 @@ jobs:
       issues: 'write'
       pull-requests: 'write'
     steps:
-      - name: 'Checkout'
+      - name: 'Checkout Release Code'
         uses: 'actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8'
         with:
           ref: '${{ github.event.inputs.ref }}'
           fetch-depth: 0
+          path: 'release'
 
       - name: 'Setup Node.js'
         uses: 'actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020' # ratchet:actions/setup-node@v4
         with:
-          node-version-file: '.nvmrc'
+          node-version-file: './release/.nvmrc'
           cache: 'npm'
 
       - name: 'Install Dependencies'
+        working-directory: './release'
         run: 'npm ci'
 
       - name: 'Run Tests'
         if: "${{github.event.inputs.force_skip_tests != 'true'}}"
         uses: './.github/actions/run-tests'
+        working-directory: './release'
         with:
           gemini_api_key: '${{ secrets.GEMINI_API_KEY }}'
 
       - name: 'Get Nightly Version'
         id: 'nightly_version'
+        working-directory: './release'
         env:
           GH_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
         run: |
@@ -73,6 +77,7 @@ jobs:
           github-token: '${{ secrets.GITHUB_TOKEN }}'
           dry-run: '${{ github.event.inputs.dry_run }}'
           previous-tag: '${{ steps.nightly_version.outputs.PREVIOUS_TAG }}'
+          working-directory: './release'
 
       - name: 'Create and Merge Pull Request'
         uses: './.github/actions/create-pull-request'
@@ -82,6 +87,7 @@ jobs:
           pr-body: 'Automated version bump for nightly release.'
           github-token: '${{ secrets.GEMINI_CLI_ROBOT_GITHUB_PAT }}'
           dry-run: '${{ github.event.inputs.dry_run }}'
+          working-directory: './release'
 
       - name: 'Create Issue on Failure'
         if: '${{ failure() && github.event.inputs.dry_run == false }}'