ci: add lint, test matrix and build workflow

.github/workflows/ci.yml

@@ -0,0 +1,65 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    name: Lint & format
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.11", "3.12", "3.13"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: uv sync --extra dev
+      - name: Ruff check
+        run: uv run ruff check nepali_payment tests examples/payments
+      - name: Ruff format check
+        run: uv run ruff format --check nepali_payment tests examples/payments
+
+  test:
+    name: Test (Python ${{ matrix.python-version }} · Django ${{ matrix.django-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.11", "3.12", "3.13"]
+        django-version: ["4.2", "5.0"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: uv sync --extra dev
+      - name: Install Django ${{ matrix.django-version }}
+        run: uv pip install "Django~=${{ matrix.django-version }}.0"
+      - name: Run tests with coverage gate
+        run: uv run pytest --cov=nepali_payment --cov-fail-under=80
+
+  build:
+    name: Build package
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v5
+        with:
+          python-version: "3.12"
+      - name: Build sdist and wheel
+        run: uv build
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/