revert: remove fork-only changes from release sync

Revert payment/wechat, sora/claude-max cleanup, fork-only migrations,
and cosmetic changes that were brought in by the release sync commit.
Keep only channel-monitor related improvements:
- PublicSettingsInjectionPayload named struct with drift test
- ChannelMonitorRunner graceful shutdown in wire
- image_output_price in SupportedModelChip
- Simplified buildSelfNavItems in AppSidebar
- Gateway WARN logs for 503 branches

frontend/src/components/payment/PaymentStatusPanel.vue

@@ -84,6 +84,9 @@
             </div>
           </div>
           <p v-if="scanHint" class="text-center text-sm text-gray-500 dark:text-gray-400">{{ scanHint }}</p>
+          <button v-if="payUrl" class="btn btn-secondary text-sm" @click="reopenPopup">
+            {{ t('payment.qr.openPayWindow') }}
+          </button>
         </div>
       </div>
       <div class="card p-4 text-center">