Add Qdrant and ChromaDB support to the project

- Added Qdrant service to both docker-compose files for production and development.
- Updated environment variables in .env.example and settings.py to include Qdrant configuration.
- Included necessary dependencies for Qdrant and ChromaDB in requirements.txt.
- Updated .gitignore to exclude ChromaDB data files.

rag/client.py

@@ -0,0 +1,19 @@
+"""
+کلاینت Qdrant — اتصال به دیتابیس وکتور
+"""
+from qdrant_client import QdrantClient
+from qdrant_client.http import models as qmodels
+
+from .config import QdrantConfig, load_rag_config
+
+
+def get_qdrant_client(config: QdrantConfig | None = None) -> QdrantClient:
+    """
+    ایجاد کلاینت Qdrant.
+    اگر config داده نشود، از rag_config.yaml بارگذاری می‌شود.
+    """
+    if config is None:
+        rag = load_rag_config()
+        config = rag.qdrant
+
+    return QdrantClient(host=config.host, port=config.port)