Keep published Korean count examples aligned with the shipped helper

The korean-character-count feature guide drifted from the verified NEIS helper output, so this follow-up adds a docs regression that executes the live command and corrects the stale byte example in the feature doc.

Constraint: The skill promises deterministic exact counts in both docs and CLI output
Rejected: Hardcode a separate doc-only expected value in tests | would still allow the published example to drift from the helper
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: When docs publish exact count values, keep them pinned to live helper output rather than a copied constant
Tested: node --test scripts/skill-docs.test.js scripts/test_korean_character_count.js
Tested: node scripts/korean_character_count.js --text '가나다' --format json
Tested: node scripts/korean_character_count.js --file <tmpfile> --profile neis --format text
Tested: printf '한\r\n나' | node scripts/korean_character_count.js --stdin --format json
Tested: npm test
Tested: npm run ci
Not-tested: none

docs/features/korean-character-count.md

@@ -82,7 +82,7 @@ node scripts/korean_character_count.js --text $'첫 줄\n둘째 줄🙂' --profi
 profile: neis
 characters: 9
 lines: 2
-bytes: 24
+bytes: 23
 ```
 
 ### 파일 입력

scripts/skill-docs.test.js

@@ -1789,6 +1789,29 @@ test("repository docs advertise the korean-character-count skill and determinist
   assert.equal(fs.existsSync(path.join(repoRoot, "packages", "korean-character-count")), false);
 });
 
+test("korean-character-count feature doc NEIS example matches live helper output", () => {
+  const featureDoc = read(path.join("docs", "features", "korean-character-count.md"));
+  const helperOutput = childProcess.execFileSync(
+    "node",
+    [
+      "scripts/korean_character_count.js",
+      "--text",
+      "첫 줄\n둘째 줄🙂",
+      "--profile",
+      "neis",
+      "--format",
+      "text",
+    ],
+    { cwd: repoRoot, encoding: "utf8" },
+  );
+  const bytesMatch = helperOutput.match(/^bytes:\s+(\d+)$/m);
+
+  assert.ok(bytesMatch, `expected helper text output to include a bytes line, got: ${helperOutput}`);
+  assert.equal(bytesMatch[1], "23");
+  assert.match(featureDoc, new RegExp(String.raw`bytes:\s+${bytesMatch[1]}`));
+  assert.match(featureDoc, /bytes=23/);
+});
+
 test("korean-character-count install payload includes the documented helper command", () => {
   const tempRoot = fs.mkdtempSync(path.join(os.tmpdir(), "korean-character-count-"));
   const installedSkillPath = path.join(tempRoot, "korean-character-count");