fix: add Gitea Actions CI workflow for automated testing

.gitea/workflows/ci.yml

@@ -1,7 +1,33 @@
 name: CI
-on: [push]
+
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
 jobs:
   test:
     runs-on: ubuntu-latest
+
     steps:
-      - run: echo hello
+      - 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 --upgrade pip
+          pip install -e ".[dev]"
+
+      - name: Run tests
+        run: |
+          PYTHONPATH=src python -m pytest tests/ -v --tb=short
+
+      - name: Run linting
+        run: |
+          pip install ruff
+          ruff check .