Refactor: Extract inline JS to external files

New JS files:
- auth.js: Password toggle, confirmation validation, copy, regenerate
- generate.js: Form controls, credential display, memory story generation

Updated templates to use external JS:
- login.html, setup.html, account.html
- admin/user_new.html, user_created.html, password_reset.html
- generate.html (now uses generate.js + minimal Jinja-dependent inline)

Core stegasoo.js (943 lines) unchanged - already handles encode/decode

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontends/web/templates/account.html

@@ -90,26 +90,8 @@
 {% endblock %}
 
 {% block scripts %}
+<script src="{{ url_for('static', filename='js/auth.js') }}"></script>
 <script>
-function togglePassword(inputId, btn) {
-    const input = document.getElementById(inputId);
-    const icon = btn.querySelector('i');
-    if (input.type === 'password') {
-        input.type = 'text';
-        icon.classList.replace('bi-eye', 'bi-eye-slash');
-    } else {
-        input.type = 'password';
-        icon.classList.replace('bi-eye-slash', 'bi-eye');
-    }
-}
-
-document.getElementById('accountForm')?.addEventListener('submit', function(e) {
-    const newPass = document.getElementById('newPasswordInput').value;
-    const confirm = document.getElementById('newPasswordConfirmInput').value;
-    if (newPass !== confirm) {
-        e.preventDefault();
-        alert('New passwords do not match');
-    }
-});
+StegasooAuth.initPasswordConfirmation('accountForm', 'newPasswordInput', 'newPasswordConfirmInput');
 </script>
 {% endblock %}