Replace CircleCI with GitHub Actions

- Remove old CircleCI config (tested Python 3.4-3.7, used JFrog)
- Add GitHub Actions CI: test on Python 3.10-3.13, lint with ruff, build package
- Tests run on all PRs and pushes to master/main

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dkijania

.circleci/config.yml

@@ -0,0 +1,54 @@
+name: CI
+
+on:
+  push:
+    branches: [master, main]
+  pull_request:
+    branches: [master, main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[dev]"
+
+      - name: Lint
+        run: ruff check src/ tests/
+
+      - name: Run tests
+        run: pytest -v
+
+  build:
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Build package
+        run: |
+          pip install build
+          python -m build
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/