Adds ClientService.SyncInbound that reconciles the new tables from
each inbound's clients list whenever existing service paths mutate
settings.clients. Wires it into AddInbound, UpdateInbound,
AddInboundClient, UpdateInboundClient, DelInboundClient,
DelInboundClientByEmail, DelDepletedClients, autoRenewClients, and
the timestamp-backfill path in adjustTraffics, plus DetachInbound
on DelInbound.
GetXrayConfig now builds settings.clients from the new tables before
writing config.json, and getInboundsBySubId joins through them
instead of JSON_EACH on settings JSON. Live Xray config and
subscription endpoints are now driven by the relational view;
settings.clients JSON stays in step as a side effect of every write.
