Add support for E2E testing infrastructure and OAuth configurations

- Introduced make commands for E2E tests using Testcontainers and Schemathesis.
- Updated `.env.demo` with configurable OAuth settings for Google and GitHub.
- Enhanced `README.md` with updated environment setup instructions.
- Added E2E testing dependencies and markers in `pyproject.toml` for real PostgreSQL and API contract validation.
- Included new libraries (`arrow`, `attrs`, `docker`, etc.) for testing and schema validation workflows.

.env.template

@@ -25,7 +25,25 @@ FIRST_SUPERUSER_EMAIL=admin@example.com
 # Default weak passwords like 'Admin123' are rejected
 FIRST_SUPERUSER_PASSWORD=YourStrongPassword123!
 
+# OAuth Configuration (Social Login)
+# Set OAUTH_ENABLED=true and configure at least one provider
+OAUTH_ENABLED=false
+OAUTH_AUTO_LINK_BY_EMAIL=true
+
+# Google OAuth (from Google Cloud Console > APIs & Services > Credentials)
+# https://console.cloud.google.com/apis/credentials
+# OAUTH_GOOGLE_CLIENT_ID=your-google-client-id.apps.googleusercontent.com
+# OAUTH_GOOGLE_CLIENT_SECRET=your-google-client-secret
+
+# GitHub OAuth (from GitHub > Settings > Developer settings > OAuth Apps)
+# https://github.com/settings/developers
+# OAUTH_GITHUB_CLIENT_ID=your-github-client-id
+# OAUTH_GITHUB_CLIENT_SECRET=your-github-client-secret
+
 # Frontend settings
 FRONTEND_PORT=3000
+FRONTEND_URL=http://localhost:3000
 NEXT_PUBLIC_API_URL=http://localhost:8000
+NEXT_PUBLIC_API_BASE_URL=http://localhost:8000
+NEXT_PUBLIC_APP_URL=http://localhost:3000
 NODE_ENV=development