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/internal/repository/usage_log_repo.go

@@ -3080,7 +3080,7 @@ func (r *usageLogRepository) GetGroupStatsWithFilters(ctx context.Context, start
 	query := `
 		SELECT
 			COALESCE(ul.group_id, 0) as group_id,
-			COALESCE(g.name, '') as group_name,
+			COALESCE(g.name, '(无分组)') as group_name,
 			COUNT(*) as requests,
 			COALESCE(SUM(ul.input_tokens + ul.output_tokens + ul.cache_creation_tokens + ul.cache_read_tokens), 0) as total_tokens,
 			COALESCE(SUM(ul.total_cost), 0) as cost,