Restore apply_template runtime default (required by Python syntax)

Python requires that parameters with defaults precede those without.
Since name and template_id have defaults, runtime must too.

Author: jerelvelarde

apps/agent/src/templates.py

@@ -79,7 +79,7 @@ def list_templates(runtime: ToolRuntime):
 
 
 @tool
-def apply_template(name: str = "", template_id: str = "", runtime: ToolRuntime):
+def apply_template(name: str = "", template_id: str = "", runtime: ToolRuntime = None):
     """
     Retrieve a saved template's HTML so you can adapt it with new data.
     After calling this, generate a NEW widget in the same style and render via widgetRenderer.