feat: add Python app package template

- Create Python application Dockerfile template
- Create Python app CloudronManifest.json template
- Create Python app start.sh template
- Include Django and Flask support
- PostgreSQL integration with wait logic
- Django migrations and collectstatic
- Admin user creation support
- Environment variable configuration
- Health check implementation

Template features:
- Python 3-slim base image
- PostgreSQL addon support
- Localstorage addon support
- Database wait and connection logic
- Django-specific support (migrations, collectstatic, admin creation)
- Flask support (simple startup)
- Configurable workers (NUM_WORKERS)
- Port 5000 (configurable)
- Health check endpoint

Environment variables:
- DJANGO_SETTINGS_MODULE: Django settings module
- SECRET_KEY: Django secret key
- ALLOWED_HOSTS: Allowed hosts for Django
- DATABASE_URL: PostgreSQL connection URL (auto-generated)
- ADMIN_USERNAME: Admin username (optional)
- ADMIN_EMAIL: Admin email (optional)
- ADMIN_PASSWORD: Admin password (optional)
- NUM_WORKERS: Gunicorn workers (default: 4)

💘 Generated with Crush

Assisted-by: GLM-4.7 via Crush <crush@charm.land>

Package-Templates/python-app/CloudronManifest.json.template

@@ -0,0 +1,31 @@
+{
+  "version": 1,
+  "manifestVersion": 2,
+  "type": "app",
+  "id": "io.cloudron.example-python-app",
+  "title": "Example Python App",
+  "description": "Example Python web application. Demonstrates basic Flask application with PostgreSQL integration for Cloudron packaging.",
+  "author": "TSYS Cloudron Project",
+  "website": "https://cloudron.io",
+  "contactEmail": "cloudron@tsys.dev",
+  "tagline": "Example Python web application",
+  "version": "1.0.0",
+  "healthCheckPath": "/",
+  "httpPort": 5000,
+  "memoryLimit": 512,
+  "addons": {
+    "localstorage": true,
+    "postgresql": {
+      "version": "14"
+    }
+  },
+  "tcpPorts": {
+    "HTTP_PORT": {
+      "description": "Flask HTTP port",
+      "defaultValue": 5000
+    }
+  },
+  "mediaLinks": [],
+  "changelog": "Initial example Cloudron package",
+  "icon": "file://logo.png"
+}