fix: restore app.js after sed truncation, update nav title to EverShelf

- Recover app.js from pre-rebrand commit and re-apply all substitutions safely
- Fix all localStorage keys: dispensa_* -> evershelf_* (settings, setup, lang)
- Fix TTS test strings: 'Dispensa Manager' -> 'EverShelf'
- Set nav.title to EverShelf in it/en/de translations and HTML fallback
- Fix JS syntax error (Unexpected end of input) that broke the site
- CI JavaScript Lint should now pass

assets/js/app.js

@@ -172,6 +172,7 @@ function changeLanguage(lang) {
     if (lang === _currentLang) return;
     localStorage.setItem('evershelf_lang', lang);
     location.reload();
+}
 
 const LOCATIONS = {
     'dispensa': { icon: '🗄️', label: 'Dispensa' },