fix(clients): seed all clients when settings.clients has string tgId

The ClientsTable seeder unmarshaled each settings.clients entry into
model.Client and silently `continue`d on error. Older inbounds wrote
tgId as an empty string for every client past the first; that fails to
unmarshal into int64, so only the first client per inbound landed in
the new clients table.

Normalize tgId and the other int64/int fields on the raw map before
marshal+unmarshal: parseable strings convert, empty/unparseable ones
drop so the field falls back to zero. Also log on the residual
unmarshal-failure path so the next regression is visible.

Recover already-seeded installs by re-syncing each inbound's clients
into the relational tables from MigrationRequirements, so running
`x-ui migrate` heals partial seeds.

web/service/inbound.go

@@ -2924,6 +2924,12 @@ func (s *InboundService) MigrationRequirements() {
 				}
 			}
 		}
+
+		// Heal clients table for installs where the one-shot seeder
+		// skipped clients due to a tgId-string unmarshal error.
+		if syncErr := s.clientService.SyncInbound(tx, inbounds[inbound_index].Id, modelClients); syncErr != nil {
+			logger.Warning("MigrationRequirements sync clients failed:", syncErr)
+		}
 	}
 	tx.Save(inbounds)