feat: set up monorepo scaffold with Yarn workspaces, Django API, React/Vite web, and Docker Compose

- Root package.json with Yarn workspaces (web, api)
- /web: React 19 + Vite 6 + @vitejs/plugin-react
  - index.html, src/main.jsx, src/App.jsx, vite.config.js
- /api: Django 5.x managed with uv
  - pyproject.toml with Django + psycopg2-binary
  - project/settings.py with PostgreSQL config from DATABASE_URL
  - project/urls.py, project/wsgi.py, manage.py
- docker-compose.yml with db (postgres:15), api, web services
  - Health check for db, live code volumes, dependency ordering
- Dockerfiles for both web (node:20-alpine) and api (python:3.12-slim)
- .gitignore updated for Python build artifacts and venv
- docs/implementation-issue-1-monorepo-scaffold.md

api/manage.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+
+import os
+import sys
+
+
+def main() -> None:
+    """Run administrative tasks."""
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == "__main__":
+    main()