fix(deps): pin a2a-sdk>=0.2.16 to resolve #572 (#581)

Co-authored-by: Jeremiah <jbill7696@gmail.com>

Author: minorun365

pyproject.toml

@@ -96,6 +96,7 @@ sagemaker = [
 ]
 
 a2a = [
+    "a2a-sdk>=0.2.16,<1.0.0",
     "a2a-sdk[sql]>=0.2.11,<1.0.0",
     "uvicorn>=0.34.2,<1.0.0",
     "httpx>=0.28.1,<1.0.0",
@@ -321,4 +322,4 @@ style = [
     ["instruction", ""],
     ["text", ""],
     ["disabled", "fg:#858585 italic"]
-]
+]