Add critical rules: always Tailwind, always translate user text

- Strengthen CLAUDE.md rule 8: Tailwind with no exceptions
- Add CLAUDE.md rule 13: all user-visible text must use translation
  functions (Twig: | translate, PHP: t_var(), JS: CmsApi.t_var())
- Add t_var() reference to hooks-and-api.md and css-js-conventions.md
- Update translate entry in quick-reference.md with all 3 contexts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/quick-reference.md

@@ -55,7 +55,7 @@
 | `module` | `'module_id' \| module({params})` |
 | `queryDB` | `'SELECT ...' \| queryDB()` |
 | `imagec` | `path \| imagec(width)` |
-| `translate` | `'text' \| translate` |
+| `translate` | `'text' \| translate` (Twig) / `t_var('text')` (PHP) / `CmsApi.t_var('text')` (JS) |
 | `json_decode` | `'json_string' \| json_decode` |
 | `raw` | `variable \| raw` |
 | `truncate` | `text \| truncate(100)` |