CI: backend pytest and frontend test and build on pull requests

.github/workflows/ci.yml

@@ -0,0 +1,54 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+jobs:
+  backend:
+    name: Backend (pytest, Python 3.12)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: pip
+          cache-dependency-path: pyproject.toml
+
+      # Only what the backend tests import. The ML stack (torch, cleanlab, sentence-transformers,
+      # bertopic, scikit-learn) is not needed: no backend module imports it at import time.
+      - name: Install test dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install \
+            "fastapi>=0.115.0" "uvicorn[standard]>=0.30.0" \
+            "sqlalchemy[asyncio]>=2.0.0" "aiosqlite>=0.20.0" "alembic>=1.13.0" \
+            "pydantic>=2.0.0" "pydantic-settings>=2.0.0" "python-multipart>=0.0.9" \
+            "aiofiles>=24.0.0" "numpy>=1.26.0" "pandas>=2.2.0" \
+            "pytest>=8.0.0" "pytest-asyncio>=0.23.0" "httpx>=0.27.0"
+
+      - name: pytest
+        run: python -m pytest -q
+
+  frontend:
+    name: Frontend (npm ci, test, build)
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: frontend
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          # the node --test files are TypeScript, which Node runs directly from 23.6
+          node-version: "24"
+          cache: npm
+          cache-dependency-path: frontend/package-lock.json
+
+      - run: npm ci
+      - run: npm test
+      - run: npm run build