feat: allow modification of built-in tool types

Remove restrictions on updating and deleting built-in tool types.
Show delete button for all tool types in Tool Workshop.

apps/api/src/api/tool_types.py

@@ -406,8 +406,7 @@ async def update_tool_type(
     if tool_type is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="tool type not found")
     
-    if tool_type.is_builtin:
-        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="cannot modify built-in tool types")
+    # Built-in tool types can now be modified
     
     update_data = data.model_dump(exclude_unset=True)
     
@@ -625,8 +624,7 @@ async def delete_tool_type(
     if tool_type is None:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="tool type not found")
     
-    if tool_type.is_builtin:
-        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="cannot delete built-in tool types")
+    # Built-in tool types can now be deleted
     
     await session.delete(tool_type)
     await session.commit()