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/__init__.py

@@ -0,0 +1,25 @@
+"""
+ماژول RAG — پایگاه دانش CropLogic
+فاز یک: Qdrant به‌عنوان vector store
+"""
+
+from .chunker import chunk_text, chunk_texts
+from .client import get_qdrant_client
+from .config import load_rag_config
+from .embedding import embed_single, embed_texts
+from .ingest import ingest, load_sources
+from .retrieve import search_with_query
+from .vector_store import QdrantVectorStore
+
+__all__ = [
+    "chunk_text",
+    "chunk_texts",
+    "embed_single",
+    "embed_texts",
+    "get_qdrant_client",
+    "ingest",
+    "load_rag_config",
+    "load_sources",
+    "QdrantVectorStore",
+    "search_with_query",
+]