sync: bring over remaining release/custom-0.1.115 changes

- Extract PublicSettingsInjectionPayload named struct with drift test
- Add channel_monitor_default_interval_seconds to SSR injection
- Add image_output_price to SupportedModelChip
- Simplify AppSidebar buildSelfNavItems (admins see available channels)
- Add gateway WARN logs for 503 no-available-accounts branches
- Wire ChannelMonitorRunner into provideCleanup for graceful shutdown
- Add migrations 130/131 (CC template userid fix + mimicry field cleanup)
- Clean up fork-only features (sora, claude max simulation, client affinity)
- Remove ~320 obsolete i18n keys
- Add codexUsage utility, WechatServiceButton, BulkEditAccountModal
- Tidy go.sum

frontend/src/components/channels/SupportedModelChip.vue

@@ -90,6 +90,13 @@
                 :unit="t(prefixKey('unitPerMillion'))"
                 :scale="perMillionScale"
               />
+              <PricingRow
+                v-if="model.pricing.image_output_price != null && model.pricing.image_output_price > 0"
+                :label="t(prefixKey('imageOutputPrice'))"
+                :value="model.pricing.image_output_price"
+                :unit="t(prefixKey('unitPerMillion'))"
+                :scale="perMillionScale"
+              />
             </template>
 
             <PricingRow