fix: admin branding — English labels, effective color saving, full coverage

- All Arabic labels replaced with English descriptive labels
- API save_theme now also writes local theme.json (prevents stale overrides)
- Added Ludo Board Colors section (9 controls)
- Added Backgammon Board Colors section (14 controls)
- Page lang/dir switched from ar/rtl to en/ltr
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

api/branding.php

@@ -53,7 +53,6 @@ if ($method === 'POST') {
         $values = $input['values'] ?? [];
         foreach ($values as $key => $value) {
             if (empty($key) || $value === null) continue;
-            // Upsert: try update first, if no rows affected, insert
             $existing = $sdb->get('platform_theme', ['id' => 'eq.' . $key, 'select' => 'id', 'limit' => 1]);
             if (!empty($existing) && !isset($existing['error'])) {
                 $sdb->update('platform_theme', ['value' => $value], ['id' => 'eq.' . $key]);
@@ -69,6 +68,13 @@ if ($method === 'POST') {
                 ]);
             }
         }
+        // Also update local theme.json so admin page stays in sync
+        $themeFile = __DIR__ . '/../public/assets/brand/theme.json';
+        $brandDir = dirname($themeFile);
+        if (!is_dir($brandDir)) mkdir($brandDir, 0777, true);
+        $local = file_exists($themeFile) ? (json_decode(file_get_contents($themeFile), true) ?: []) : [];
+        $local = array_merge($local, $values);
+        file_put_contents($themeFile, json_encode($local, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE));
         jsonResponse(['success' => true]);
     }