fix(node-sync): merge client enable with boolean AND for PostgreSQL

The per-client traffic merge built enable = CASE WHEN ? = 0 THEN 0 ELSE enable END, mixing an integer literal with the boolean enable column. PostgreSQL rejects this with SQLSTATE 42804, aborting every node traffic merge transaction every 5s and freezing all up/down/last_online accounting on Postgres main panels. Replace with enable AND ?, which is type-safe on Postgres (boolean AND boolean) and identical in semantics on SQLite: the node may only disable a client, never re-enable one the panel already disabled.

Closes #4964

web/service/inbound.go

@@ -1760,7 +1760,7 @@ func (s *InboundService) setRemoteTrafficLocked(nodeID int, snap *runtime.Traffi
 			// from the node arriving after a central disable would otherwise
 			// overwrite enable=false back to true, letting the client accumulate
 			// far more traffic than their limit before being disabled again.
-			enableExpr := "CASE WHEN ? = 0 THEN 0 ELSE enable END"
+			enableExpr := "enable AND ?"
 			if err := tx.Exec(
 				fmt.Sprintf(
 					`UPDATE client_traffics