refactor: move FILE_PREFIX constant to top with DEFAULT_TOOLS

- Organize module constants together at the top
- Keep FILE_PREFIX and DEFAULT_TOOLS in same location for consistency

🤖 Assisted by Amazon Q Developer

Author: mrlee-amazon

src/strands/experimental/agent_config.py

@@ -7,6 +7,9 @@
 
 from .tool_pool import ToolPool
 
+# File prefix for configuration file paths
+FILE_PREFIX = "file://"
+
 # Minimum viable list of tools to enable agent building
 # This list is experimental and will be revisited as tools evolve
 DEFAULT_TOOLS = ["file_read", "editor", "http_request", "shell", "use_agent"]
@@ -15,8 +18,6 @@
 class AgentConfig:
     """Agent configuration with toAgent() method and ToolPool integration."""
 
-    FILE_PREFIX = "file://"
-    
     def __init__(self, config_source: str | dict[str, any], tool_pool: "ToolPool | None" = None):
         """Initialize AgentConfig from file path or dictionary.
         
@@ -26,11 +27,11 @@ def __init__(self, config_source: str | dict[str, any], tool_pool: "ToolPool | N
         """
         if isinstance(config_source, str):
             # Require file:// prefix for file paths
-            if not config_source.startswith(self.FILE_PREFIX):
-                raise ValueError(f"File paths must be prefixed with '{self.FILE_PREFIX}'")
+            if not config_source.startswith(FILE_PREFIX):
+                raise ValueError(f"File paths must be prefixed with '{FILE_PREFIX}'")
 
             # Remove file:// prefix and load from file
-            file_path = config_source.removeprefix(self.FILE_PREFIX)
+            file_path = config_source.removeprefix(FILE_PREFIX)
             with open(file_path, 'r') as f:
                 config_data = json.load(f)
         else: