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

backend/cmd/server/wire.go

@@ -97,6 +97,7 @@ func provideCleanup(
 	scheduledTestRunner *service.ScheduledTestRunnerService,
 	backupSvc *service.BackupService,
 	paymentOrderExpiry *service.PaymentOrderExpiryService,
+	channelMonitorRunner *service.ChannelMonitorRunner,
 ) func() {
 	return func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
@@ -239,6 +240,12 @@ func provideCleanup(
 				}
 				return nil
 			}},
+			{"ChannelMonitorRunner", func() error {
+				if channelMonitorRunner != nil {
+					channelMonitorRunner.Stop()
+				}
+				return nil
+			}},
 		}
 
 		infraSteps := []cleanupStep{