chore: add GitHub Actions workflow for Python app CI

Introduce a CI workflow to automate testing for the Python app. The workflow triggers on pushes to `main`, tags matching `v*.*.*`, and pull requests. It sets up Python, installs dependencies, and runs pre-commit checks to ensure code quality.

Author: jkawamoto

.github/workflows/python-app.yaml

@@ -0,0 +1,25 @@
+name: Python Application
+on:
+  push:
+    branches: [main]
+    tags:
+      - "v*.*.*"
+  pull_request:
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+        with:
+          enable-cache: true
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version-file: pyproject.toml
+      - name: Install the project
+        run: uv sync --all-extras --dev
+      - name: Check files
+        run: uv run pre-commit run -a