feat:update heurist env var examples

Author: tsubasakong

.env.example

@@ -228,8 +228,10 @@ LARGE_ANTHROPIC_MODEL=  # Default: claude-3-5-sonnet-20241022
 HEURIST_API_KEY=      # Get from https://heurist.ai/dev-access
 SMALL_HEURIST_MODEL=  # Default: meta-llama/llama-3-70b-instruct
 MEDIUM_HEURIST_MODEL= # Default: meta-llama/llama-3-70b-instruct
-LARGE_HEURIST_MODEL=  # Default: meta-llama/llama-3.1-405b-instruct
-HEURIST_IMAGE_MODEL=  # Default: PepeXL
+LARGE_HEURIST_MODEL=  # Default: meta-llama/llama-3.3-70b-instruct
+HEURIST_IMAGE_MODEL=  # Default: FLUX.1-dev
+HEURIST_EMBEDDING_MODEL= # Default: BAAI/bge-large-en-v1.5
+USE_HEURIST_EMBEDDING= # Set to TRUE for HEURIST embedding, leave blank for local
 
 # Gaianet Configuration
 GAIANET_MODEL=