docs: the comparison table claims 24 rules, the package defines 22 (#35)

Author: shenxianpeng

docs/compare/tools.md

@@ -16,7 +16,7 @@ for the current state. GitHub's own rulesets are on
 | [commitcheck](https://github.com/marketplace/commitcheck) | A hosted App that applies one regular expression, set in its web admin | Commit message, pull request title or description, by regex | GitHub App | Free for public repositories; $25 a month for private ones |
 | [DCO app](https://github.com/apps/dco) and [DCO-2](https://github.com/cncf/dco2) | The sign-off check the Linux kernel and the CNCF use, with a remediation flow for missing sign-offs | `Signed-off-by` trailers | GitHub App | Free, open source |
 | [PRLint](https://github.com/ewolfe/prlint), [PR Title Checker](https://github.com/marketplace/actions/pr-title-checker) | Regular expressions over pull request fields | Title, body, labels, branch | App / Action | Free, open source |
-| **Commit Check** | One rule engine with [24 documented rules](../rules.md), run as a hook, a CLI, an Action, a hosted App or an MCP tool | Commit message, branch name, author name and email, sign-off, AI attribution, force pushes, file size and paths, tag names; the squash message of a pull request | All of the above | Free, open source; the App's private organization repositories move to a paid plan later |
+| **Commit Check** | One rule engine with [22 documented rules](../rules.md), run as a hook, a CLI, an Action, a hosted App or an MCP tool | Commit message, branch name, author name and email, sign-off, AI attribution, force pushes, file size and paths, tag names; the squash message of a pull request | All of the above | Free, open source; the App's private organization repositories move to a paid plan later |
 
 ## What is different about Commit Check
 

tests/docs_sync_test.py

@@ -133,6 +133,28 @@ def test_every_rule_explains_itself(self):
                     f"{entry.rule_id} ({entry.check}) section is missing {required}"
                 )
 
+    def test_prose_rule_counts_match_the_catalog(self):
+        """A page that counts the rules out loud must count them correctly.
+
+        The comparison table sells the engine on how much it covers, so a
+        stale number there is worse than no number: it is the one figure a
+        reader checks against the rules page. Every other test here proves a
+        rule is *documented*; none of them read a sentence that says how
+        many there are.
+        """
+        expected = len(ALL_RULES)
+        for path in sorted(DOCS.rglob("*.md")):
+            if path.parent.name == "posts":
+                continue  # blog posts are dated records; see AGENTS.md
+            for claimed in _PROSE_RULE_COUNT.findall(path.read_text(encoding="utf-8")):
+                assert int(claimed) == expected, (
+                    f"{path.relative_to(DOCS.parent)} claims {claimed} rules, "
+                    f"but the package defines {expected}"
+                )
+
+
+#: A prose claim about how many rules exist, e.g. ``24 documented rules``.
+_PROSE_RULE_COUNT = re.compile(r"(\d+) documented rules")
 
 #: A pre-commit revision pin, e.g. ``rev: v2.13.1``.
 _REV_PIN = re.compile(r"^\s*rev:\s*v(\d+\.\d+\.\d+)\s*$", re.M)