fix: allow lexical import shadowing

test/wcc/data/paramshadowmod/crossmod/crossmod.ww

@@ -1,8 +1,6 @@
-// crossmod — directory package whose probe() takes a param named like the
-// module `shadowmod` that paramshadowmod (NOT crossmod) imports. The
-// shadow rule is filtered by the binding's own module (src_imports
-// cur_mod filter): crossmod carries no `import shadowmod`, so this param
-// must NOT trip even though a sibling package imports that leaf.
+// crossmod — directory package whose probe() takes a parameter named like the
+// module `shadowmod` that a sibling package imports.  Since crossmod itself has
+// no such file-local package-name object, this is an ordinary parameter.
 
 package crossmod;