Add RAG configuration options and enhance parameter configurability

- Add top-k and cosine-threshold parms for api server
- Update .env and cli parms handling with new parameters
- Improve splash screen display
- Update bash and storage classes to read new parameters from .env file.

.env.example

@@ -6,6 +6,17 @@ PORT=9621
 WORKING_DIR=/app/data/rag_storage
 INPUT_DIR=/app/data/inputs
 
+# RAG Configuration
+MAX_ASYNC=4
+MAX_TOKENS=32768
+EMBEDDING_DIM=1024
+MAX_EMBED_TOKENS=8192
+#HISTORY_TURNS=3
+#CHUNK_SIZE=1200
+#CHUNK_OVERLAP_SIZE=100
+#COSINE_THRESHOLD=0.2
+#TOP_K=50
+
 # LLM Configuration (Use valid host. For local services, you can use host.docker.internal)
 # Ollama example
 LLM_BINDING=ollama
@@ -38,15 +49,6 @@ EMBEDDING_MODEL=bge-m3:latest
 # EMBEDDING_BINDING_HOST=http://host.docker.internal:9600
 # EMBEDDING_MODEL=bge-m3:latest
 
-# RAG Configuration
-MAX_ASYNC=4
-MAX_TOKENS=32768
-EMBEDDING_DIM=1024
-MAX_EMBED_TOKENS=8192
-#HISTORY_TURNS=3
-#CHUNK_SIZE=1200
-#CHUNK_OVERLAP_SIZE=100
-
 # Security (empty for no key)
 LIGHTRAG_API_KEY=your-secure-api-key-here