ci: add test workflow so PRs and pushes to main are automatically tested

Previously tests only ran during the publish workflow on release.
Now pytest runs on every push to main and on every PR, across
Python 3.11, 3.12, and 3.13. Also updates CODEBASE_MAP.md to
document the new workflow.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

.github/workflows/test.yml

@@ -0,0 +1,22 @@
+name: Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.11", "3.12", "3.13"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: astral-sh/setup-uv@v5
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - run: uv sync --group dev
+      - run: uv run pytest

agent_docs/CODEBASE_MAP.md

@@ -26,6 +26,7 @@ src/ralphify/           # All source code
 tests/                  # Pytest tests — one test file per module
 docs/                   # MkDocs site (Material theme) — user-facing documentation
 .github/workflows/
+├── test.yml            # Run tests on push to main and PRs (Python 3.11–3.13)
 ├── docs.yml            # Deploy docs to GitHub Pages on push to main
 └── publish.yml         # Publish to PyPI on release (with test gate)
 ```