Feat: run tests on push and PR

Co-authored-by: gpt-5.3-codex <no-reply@openai.com>

.github/workflows/test.yml

@@ -0,0 +1,23 @@
+name: test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Install stable Rust
+        run: |
+          rustup toolchain install stable --profile minimal
+          rustup default stable
+
+      - name: Run tests
+        run: cargo test --all-targets --verbose