test(quality): reword test-masking self-test comments to avoid literal masking patterns

The added allowlist-test comments contained the literal strings 'assert.ok(true)' and
'.skip' which the masking detector's own regexes match as text — making the gate flag
its own test file (net +1 tautology/skip/extended-tautology vs main). Reworded to plain
prose ('a new tautology', 'a new skip marker'); test logic unchanged (24/24 pass).

tests/unit/check-test-masking.test.ts

@@ -273,11 +273,11 @@ test("evaluateMasking: allowlist exempts ONLY reduction — tautology/skip still
       {
         file: "legit.test.ts",
         baseAsserts: 5,
-        headAsserts: 3, // reduction (exempt)
+        headAsserts: 3, // net reduction — exempt for allowlisted file
         baseTaut: 0,
-        headTaut: 1, // new assert.ok(true) (NOT exempt)
+        headTaut: 1, // a new tautology — NOT exempt
         baseSkips: 0,
-        headSkips: 1, // new .skip (NOT exempt)
+        headSkips: 1, // a new skip marker — NOT exempt
         baseExtTaut: 0,
         headExtTaut: 0,
       },