Invalidate units when loaded sources change

site/doc/pages/load.txt

@@ -12,6 +12,8 @@ Includes another UCE file.
 
 Use `#load` when you want the current file to pull in declarations or reusable content from another UCE source file.
 
+Loaded sources are tracked transitively. Changing a direct or nested `#load` dependency invalidates and recompiles the entry unit before its next execution.
+
 
 :example
 // #load "file.uce" includes another unit at COMPILE time (a preprocessor directive,