Let the theme's assets back through the exclusion

.github/workflows/docs.yml

@@ -23,6 +23,9 @@ jobs:
           python-version: "3.13"
       - run: uv sync --group docs
       - run: uv run --group docs mkdocs build --strict
+      # exclude_docs filters theme files too, and a build stripped of its
+      # stylesheets is still a green build — deploying bare HTML taught that.
+      - run: ls site/assets/stylesheets/main.*.min.css
       - uses: actions/upload-pages-artifact@v5
         with:
           path: site/

mkdocs.yml

@@ -11,9 +11,12 @@ edit_uri: ""
 # subdirectory is local working material that git already ignores and the
 # site must too. Excluding directories wholesale is the same kind of promise
 # the sdist allowlist makes: an accidental `mkdocs gh-deploy` from a working
-# checkout cannot publish anything the repository does not carry.
+# checkout cannot publish anything the repository does not carry. The theme
+# serves its stylesheets and scripts through this same filter, so its assets
+# are let back through by name — without that the site deploys as bare HTML.
 exclude_docs: |
   */
+  !assets/
 
 # CHANGELOG.md lives at the repository root, where a reader who never opens
 # the site still finds it. The hook hands that one file to the build as a