fix: allow lexical import shadowing

test/wcc/data/paramshadowmod/neg_forrange_single.ww

@@ -1,15 +1,14 @@
-// neg_forrange_single — `for (let shadowmod .. s)` single-binding
-// range loop where the loop variable shadows the imported module.
-// N_FORRANGE wires check_module_shadow on the single-name branch
-// (n->str), so the rule fires at the for header.
+// Legacy neg_forrange_single, now a positive range-binding case. The import
+// initializes total; the one-byte "A" iteration binds the closer shadowmod
+// value in the loop body. Builds and runs 42 + 65 = 107.
 
-package paramshadowmod;
+package main;
 
 import shadowmod;
 
-export fn main() i32 = {
-	let s: str = "abc";
-	let total: i32 = 0i32;
+fn main() i32 = {
+	let s: str = "A";
+	let total: i32 = shadowmod.say();
 	for (let shadowmod .. s) {
 		total += shadowmod: i32;
 	};