fix: default API base URL to api.datons.com

Public SDK now defaults to the production gateway api.datons.com
(previously mcp.datons.com). Smoke-tested against esios.archives_i90.

Author: jsulopzs

src/datons/client.py

@@ -12,7 +12,7 @@
 
 from datons.exceptions import AuthenticationError, DatonsError, QueryError, RateLimitError
 
-DEFAULT_BASE_URL = "https://mcp.datons.com"
+DEFAULT_BASE_URL = "https://api.datons.com"
 DEFAULT_TIMEOUT = 30.0