Address code review comments - improve documentation

Co-authored-by: hiyouga <16256802+hiyouga@users.noreply.github.com>

Author: Copilot

src_py/agenthub/claude4_5/client.py

@@ -74,7 +74,8 @@ def transform_uni_config_to_model_config(self, config: UniConfig) -> dict[str, A
         Transform universal configuration to Claude-specific configuration.
 
         Args:
-            config: Universal configuration dict
+            config: Universal configuration dict. If prompt_cache is not specified,
+                   defaults to PromptCache.ENABLE for Claude models.
 
         Returns:
             Claude configuration dictionary

src_py/tests/test_prompt_cache_config.py

@@ -20,7 +20,7 @@
 
 
 def test_prompt_cache_enable_config():
-    """Test that enable mode adds cache_control with 5m TTL."""
+    """Test that enable mode adds cache_control without explicit TTL (defaults to 5m)."""
     client = Claude4_5Client(model="claude-sonnet-4-5-20250929", api_key="dummy")
     config = {
         "system_prompt": "You are a helpful assistant.",