Add nightly CI base image and migrate workflows to python-repositories-ci.

Pre-build Python, uv, and locked deps in a Gitea container image so daily jobs skip repeated bootstrap; document runner registry auth and ci-bot credentials.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitea/workflows/code-quality.yml

@@ -8,23 +8,17 @@ on:
 
 jobs:
   code-quality:
-    runs-on: ubuntu-latest
+    runs-on: python-repositories-ci
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version-file: .python-version
-
-      - name: Install uv
-        run: pip install uv
-
-      - name: Install dependencies
+      - name: Sync dependencies
         env:
           UV_LINK_MODE: copy
-        run: uv sync --all-extras
+          UV_INDEX_GITEA_USERNAME: ci-bot
+          UV_INDEX_GITEA_PASSWORD: ${{ secrets.CI_RUNNER_TOKEN }}
+        run: uv sync --all-extras --frozen
 
       - name: Type check with mypy
         run: uv run mypy .