ci: add Windows import smoke test

.github/workflows/windows_smoke.yml

@@ -0,0 +1,31 @@
+name: Windows Smoke Test
+
+# Imports every artifact module on Windows to catch OS-specific breakage
+# (extracted paths use backslash separators on Windows) that the ubuntu-only
+# lint job cannot. This checks importability, not parsing correctness.
+
+on:
+  pull_request:
+    paths:
+      - '**.py'
+      - 'requirements.txt'
+      - '.github/workflows/windows_smoke.yml'
+  workflow_dispatch:
+
+jobs:
+  windows-smoke:
+    runs-on: windows-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: python -m pip install --prefer-binary -r requirements.txt
+
+      - name: Import all artifact modules on Windows
+        run: python admin/test/scripts/test_artifact_imports.py