ci: add GitHub Actions (ruff, black, pytest, docker build)

Author: mircothibes

.github/workflows/ci.yml

@@ -0,0 +1,55 @@
+name: CI
+
+on:
+  push:
+    branches: [ main, master ]
+  pull_request:
+    branches: [ main, master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[dev]"
+          # tools (explicit, in case dev extras change)
+          pip install ruff black pytest
+
+      - name: Ruff (lint)
+        run: ruff check .
+
+      - name: Black (format check)
+        run: black --check .
+
+      - name: Pytest
+        run: pytest -q
+
+  docker-build:
+    runs-on: ubuntu-latest
+    needs: test
+    if: github.event_name == 'push' # build only on push, not PR
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build image (no push)
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          tags: mvtk/sysinfo-cli:ci
+          load: true
+