docs: add em-dash and AI-vibe pre-commit self-check to CLAUDE.md

Author: datlechin

CLAUDE.md

@@ -233,6 +233,12 @@ Applies to **everything**: docs, commit messages, CHANGELOG entries, UI strings,
 
 **No em dashes (—).** Anywhere. Use a comma, period, colon, or rewrite the sentence. Hyphens (-) for compound words are fine.
 
+Before any commit that touches user-facing strings, CHANGELOG.md, PR bodies, or files you authored this session, run:
+```bash
+git diff --cached -U0 | grep -nE '—|seamless|robust|comprehensive|intuitive|effortless|streamlined|leverage|elevate|delve|utilize|facilitate'
+```
+If anything matches, rewrite before committing.
+
 **No AI-generated filler.** If it sounds like a chatbot wrote it, rewrite it. Banned words: seamless, robust, comprehensive, intuitive, effortless, powerful (as filler), streamlined, leverage, elevate, harness, supercharge, unlock, unleash, dive into, game-changer, empower, delve, utilize, facilitate. No "Absolutely!" / "Ready to dive in?" / "Let's get started!" openers.
 
 **Be specific.** Numbers, tech names, file paths. "Runs in 200ms" beats "runs fast". "Uses `PQexecParams`" beats "uses native binding".