[Fix] Zensical doc build, add doc build check CI

.github/workflows/docs-check.yml

@@ -0,0 +1,23 @@
+name: Docs build check
+
+on:
+  pull_request:
+    paths:
+      - "docs/**"
+      - "_zensical.toml"
+      - "openg2g/**"
+      - "scripts/gen_api_docs.py"
+      - "scripts/docs.sh"
+      - "uv.lock"
+      - ".github/workflows/docs-check.yml"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: astral-sh/setup-uv@v7
+        with:
+          enable-cache: true
+      - run: uv sync --only-group docs
+      - run: uv run --no-sync bash scripts/docs.sh build

_zensical.toml

@@ -117,3 +117,10 @@ show_root_full_path = true
 members_order = "source"
 relative_crossrefs = true
 filters = ["!^_"]
+
+# mkdocstrings cross-references like [`Coordinator`][openg2g.coordinator.Coordinator]
+# are resolved by the mkdocs-autorefs plugin after Zensical's reference parser has
+# already run. Disable Zensical's pre-autorefs warning to avoid flagging refs as
+# "unresolved" that autorefs then rewrites correctly in the final HTML.
+[project.validation]
+unresolved_references = false