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/db.php

@@ -42,6 +42,7 @@ function init_db_schema(PDO $pdo): void {
             username TEXT UNIQUE NOT NULL,
             password_hash TEXT NOT NULL,
             role TEXT NOT NULL DEFAULT 'admin',
+            is_enabled INTEGER NOT NULL DEFAULT 1,
             created_at DATETIME DEFAULT CURRENT_TIMESTAMP
         );
 
@@ -86,8 +87,31 @@ function init_db_schema(PDO $pdo): void {
             kitchen_close_time TEXT NULL,
             updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
         );
+
+        -- Single-row table (id is pinned to 1) for site-wide toggles that
+        -- don't belong to any one record — starting with whether the
+        -- public menu page shows its items at all.
+        CREATE TABLE IF NOT EXISTS site_settings (
+            id INTEGER PRIMARY KEY CHECK (id = 1),
+            menu_enabled INTEGER NOT NULL DEFAULT 1,
+            updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+        );
     ");
 
+    // users.is_enabled shipped after the initial release — CREATE TABLE IF
+    // NOT EXISTS above is a no-op against an existing table, so an install
+    // from before this needs the column added explicitly, once.
+    $hasIsEnabled = false;
+    foreach ($pdo->query("PRAGMA table_info(users)") as $col) {
+        if ($col['name'] === 'is_enabled') {
+            $hasIsEnabled = true;
+            break;
+        }
+    }
+    if (!$hasIsEnabled) {
+        $pdo->exec("ALTER TABLE users ADD COLUMN is_enabled INTEGER NOT NULL DEFAULT 1");
+    }
+
     // Seed default admin user if table is empty (username: admin / password: password)
     $stmt = $pdo->query("SELECT COUNT(*) as count FROM users");
     $userCount = $stmt->fetchColumn();
@@ -125,4 +149,11 @@ function init_db_schema(PDO $pdo): void {
             }
         }
     }
+
+    // Seed the singleton settings row (menu on by default) if it doesn't exist yet.
+    $stmt = $pdo->query("SELECT COUNT(*) as count FROM site_settings");
+    $settingsCount = $stmt->fetchColumn();
+    if ($settingsCount == 0) {
+        $pdo->exec("INSERT INTO site_settings (id, menu_enabled) VALUES (1, 1)");
+    }
 }