Add Gitea Actions CI/CD workflows and ruff dependency

.gitea/workflows/pr.yml

@@ -0,0 +1,31 @@
+name: PR Gate
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  lint:
+    name: Lint (ruff)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+      - run: pip install ruff
+      - run: ruff check .
+
+  test:
+    name: Test (pytest)
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.11", "3.12"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - run: pip install -e .
+      - run: pytest tests/ -v --tb=short