refactor: define SITE_DIR once in PR preview workflow

.github/actions/build-docs/action.yml

@@ -5,21 +5,28 @@ inputs:
   subdir:
     description: Subdirectory to deploy to (e.g., dev, 1.0.0, pr/3)
     required: true
+  site-dir:
+    description: Output directory for the built site
+    default: /tmp/built-site
 
 outputs:
   site-dir:
     description: Path to the built site
-    value: /tmp/built-site
+    value: ${{ inputs.site-dir }}
 
 runs:
   using: composite
   steps:
     - shell: bash
       run: |
-        # Use github.action_path so the script always comes from the action's
-        # source (trusted main branch), not the checked-out working directory
-        # (which may contain untrusted PR code).
+        # Update the site url.
         uv run --group docs python "${{ github.action_path }}/override_site_url.py" "${{ inputs.subdir }}"
+
+        # Build the docs.
         uv run --group docs zensical build --clean
-        mv site /tmp/built-site
-        git checkout -- zensical.toml
+
+        # Move the docs to the output directory.
+        mv site "${{ inputs.site-dir }}"
+
+        # Leave the working directory clean for the next action.
+        git checkout -- .

.github/workflows/docs-pr-preview.yml

@@ -7,6 +7,9 @@ on:
   pull_request_target:
     types: [opened, synchronize, reopened]
 
+env:
+  SITE_DIR: /tmp/built-site
+
 concurrency:
   group: docs-deploy
   cancel-in-progress: false
@@ -34,11 +37,12 @@ jobs:
         id: build
         with:
           subdir: pr/${{ github.event.number }}
+          site-dir: ${{ env.SITE_DIR }}
 
       - uses: actions/upload-artifact@v4
         with:
           name: docs-preview
-          path: /tmp/built-site
+          path: ${{ env.SITE_DIR }}
           retention-days: 1
 
   deploy:
@@ -55,14 +59,14 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           name: docs-preview
-          path: /tmp/built-site
+          path: ${{ env.SITE_DIR }}
 
       # Reference the action from @main so deploy logic always comes from the
       # trusted main branch.
       - uses: TaiSakuma/improved-octo-fortnight/.github/actions/deploy-to-gh-pages@main
         id: deploy
         with:
-          site-dir: /tmp/built-site
+          site-dir: ${{ env.SITE_DIR }}
           target: pr/${{ github.event.number }}
           commit-message: "Deploy PR #${{ github.event.number }} preview"