fix: resolve staging blockers B1-B5, S6, X5 (quality review v1)

.env.example

@@ -4,7 +4,12 @@ LLM_API_KEY=sk-or-v1-xxx
 LLM_MODEL=anthropic/claude-3.5-sonnet
 LLM_API_BASE=
 
-# Auth (CHANGE THIS!)
+# MCP Tool Server — URL MUST include the /mcp path (FastMCP HTTP transport).
+# Example: http://mcp-tools:8501/mcp  (the docker-compose default already includes /mcp)
+MCP_SERVER_URL=http://mcp-tools:8501/mcp
+
+# Auth (CHANGE THIS — must be >=32 chars, must NOT be the default below)
+# Generate one with: python -c "import secrets;print(secrets.token_urlsafe(32))"
 AUTH_TOKEN=change-me-to-something-secure
 
 # Logging