The traffic-pending.json file could contain a stale client traffic delta
with inboundId=0 (created before the InboundId resolution fix). When
flushToDatabase tried to INSERT this into client_traffics, it violated
the foreign key constraint fk_inbounds_client_stats, causing the entire
transaction to roll back and blocking ALL traffic from being written to
MariaDB.
- Skip deltas with InboundID==0 in flushToDatabase with a warning log
- Share a single TrafficPendingStore between XrayTrafficJob and the
flush loop to eliminate a race condition from dual file instances
- Add test for zero InboundID skip behavior
In shared mode the Xray API returns InboundId=0 for client traffic.
Collect() now looks up the real InboundId from the client_traffics table
by email, and skips unknown emails with a warning. Also computes and
sets online clients in XrayTrafficJob since addClientTraffic is bypassed.
