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/layout/AppHeader.vue

@@ -125,6 +125,7 @@
                   <Icon name="key" size="sm" />
                   {{ t('nav.apiKeys') }}
                 </router-link>
+
                 <a
                   v-if="authStore.isAdmin"
                   href="https://github.com/Wei-Shaw/sub2api"
@@ -142,6 +143,7 @@
                   </svg>
                   {{ t('nav.github') }}
                 </a>
+
               </div>
 
               <!-- Contact Support (only show if configured) -->