Add menu enable toggle, user status, and mobile/UI polish

- Admin menu page: mobile item cards now put Actions in the top-right
  corner next to Status, matching the desktop row layout instead of
  stacking at the bottom; same treatment applied to announcements and
  users for consistency across all three admin lists
- Center button label text everywhere via .btn { justify-content: center }
  instead of one-off overrides
- Add a Disable/Enable Menu toggle to the admin menu toolbar; the public
  menu page shows its existing "menu being updated" message while disabled
- Add an Enabled/Disabled status to user accounts, with its own toggle
  badge, guardrails against disabling your own account or the last
  enabled account, and an immediate session kick for anyone disabled
  mid-session
- Fix the announcement banner / hero tagline "·" separators to hide only
  when their neighboring text actually wraps onto a different line,
  instead of a fixed breakpoint or always-on dot

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

inc/users.php

@@ -13,13 +13,13 @@ require_once __DIR__ . '/db.php';
 
 function get_all_users(): array {
     $pdo = get_db();
-    $stmt = $pdo->query("SELECT id, username, role, created_at FROM users ORDER BY username ASC");
+    $stmt = $pdo->query("SELECT id, username, role, is_enabled, created_at FROM users ORDER BY username ASC");
     return $stmt->fetchAll() ?: [];
 }
 
 function get_user_by_id(int $id): ?array {
     $pdo = get_db();
-    $stmt = $pdo->prepare("SELECT id, username, role, created_at FROM users WHERE id = ?");
+    $stmt = $pdo->prepare("SELECT id, username, role, is_enabled, created_at FROM users WHERE id = ?");
     $stmt->execute([$id]);
     $res = $stmt->fetch();
     return $res ?: null;
@@ -30,6 +30,17 @@ function count_users(): int {
     return (int) $pdo->query("SELECT COUNT(*) FROM users")->fetchColumn();
 }
 
+function count_enabled_users(): int {
+    $pdo = get_db();
+    return (int) $pdo->query("SELECT COUNT(*) FROM users WHERE is_enabled = 1")->fetchColumn();
+}
+
+function toggle_user_enabled(int $id): bool {
+    $pdo = get_db();
+    $stmt = $pdo->prepare("UPDATE users SET is_enabled = CASE WHEN is_enabled = 1 THEN 0 ELSE 1 END WHERE id = ?");
+    return $stmt->execute([$id]);
+}
+
 function username_exists(string $username, ?int $excludeId = null): bool {
     $pdo = get_db();
     if ($excludeId !== null) {