Refactor admin panel: enhance user management and security features

- Added role-based access control for user management links in admin navigation.
- Improved user account display with a dedicated account link.
- Implemented form submission confirmation for delete actions in the admin interface.
- Introduced a password visibility toggle on the login page.
- Added login throttling to prevent brute-force attacks, recording failed attempts.
- Created a CLI script for creating an admin user, replacing the previous hardcoded admin credentials.
- Updated database schema to support login attempt tracking.
- Enhanced user editing functionality, allowing role changes with restrictions.
- Improved modal handling for user actions, ensuring better focus management.
- Added styles for new account management page and improved modal transitions.

admin/login.js

@@ -0,0 +1,19 @@
+// Login page: show/hide password toggle. Both icons are in the markup;
+// this just flips which one is hidden, so no HTML is built in JS.
+
+const btn = document.getElementById('btn-toggle-login-password');
+const input = document.getElementById('password');
+
+if (btn && input) {
+	const eyeOpen = btn.querySelector('.js-eye-open');
+	const eyeOff = btn.querySelector('.js-eye-off');
+
+	btn.addEventListener('click', () => {
+		const show = input.type === 'password';
+		input.type = show ? 'text' : 'password';
+		btn.setAttribute('aria-label', show ? 'Hide password' : 'Show password');
+		eyeOpen.hidden = show;
+		eyeOff.hidden = !show;
+		input.focus();
+	});
+}