fix: correct verify-build diagnostics and close two robustness gaps (closes #180)

build.js

@@ -29,6 +29,12 @@ function repoRelative(p) {
 // reports every input that contributed to an output in the metafile, which is
 // the authoritative answer to "is constants.js in this bundle" — unlike
 // searching the minified text, it does not depend on what survived minification.
+//
+// The ".js" filter below is the only place that assumption lives:
+// script/verify-build searches every file and symlink under dist/ for a
+// marker, without filtering by extension, and hard-fails if it cannot walk the
+// whole tree, so a bundle emitted under some other extension fails there as
+// unlisted rather than escaping both checks at once.
 function outputsContainingAuditedModule(metafile) {
     return Object.entries(metafile.outputs)
         .filter(([outFile, info]) => {