Normalize env example with canonical Qdrant vars

Author: Thomas Tupper

.env.example

@@ -8,11 +8,19 @@ OLLAMA_EMBED_MODEL=nomic-embed-text
 OLLAMA_CHAT_MODEL=llama3.1:8b
 INFER_API_KEY=
 
-# store runtime
+# store runtime (canonical contract)
+# Internal default for one-node compose is service name `infer`.
 OPENAI_BASE_URL=http://infer:8081/v1
 OPENAI_API_KEY=
 MEM0_LLM_MODEL=gpt-4.1-nano
 MEM0_EMBED_MODEL=text-embedding-3-small
+
+# Qdrant config
+# Prefer QDRANT_URL when supported by the service runtime.
+QDRANT_URL=http://qdrant:6333
+QDRANT_API_KEY=
 QDRANT_COLLECTION=foxmemory
-QDRANT_HOST=127.0.0.1
+
+# Backward-compatible fields used by some builds/scripts
+QDRANT_HOST=qdrant
 QDRANT_PORT=6333