test(pm): quote the paths the comment-mask cases name, so they can fail (#8478)

Reverse-verifying the comment half — removing the mask and watching the
diagnostics — showed two of the new cases staying GREEN through the ablation.
The scan only ever reads QUOTED spans, and those two fixtures named their paths
bare inside the comment, so they asserted nothing either way. Quoted, the same
ablation reddens all three comment cases.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018WuTtyckQa1VcXwgd52JpN

Author: claude

scripts/pm/dispatch-gates.mjs

@@ -899,11 +899,17 @@ function selfTest() {
   // expensive one — a false lead is pasted into every dispatch prompt whose
   // surface brushes it — but a narrowing that also drops the real inputs would
   // just move the dishonesty.
+  // Every path a comment case names is QUOTED inside that comment, because the
+  // scan only ever reads quoted spans: an unquoted path in prose is invisible
+  // to it with or without masking, so a fixture spelling one bare would assert
+  // nothing and pass forever. Measured — the first draft of the two cases below
+  // did exactly that, and only the reverse-verification run that removed the
+  // comment mask showed them staying green through it.
   const commented = [
     '/**',
-    ' * Reads `packages/spec/src` and .changeset/x.md — prose, not inputs.',
+    ' * Reads `packages/spec/src` and `.changeset/x.md` — prose, not inputs.',
     ' */',
-    "const REAL = 'packages/rest/src';   // twin of packages/core/src, says the comment",
+    "const REAL = 'packages/rest/src';   // twin of 'packages/core/src', says the comment",
     "const U = 'https://example.com/a/b'; const AFTER_URL = 'packages/metadata/src';",
     "const RE = /['\"`]/;",
     "const AFTER_REGEX = 'packages/client/src';",