P8: GSE165845 validation scripts (prepare, §16.5 metrics) and cloud task

scripts/p8/prepare.py lays out the 360 GEO IDATs under their header barcode/position;
scripts/p8/validate_p8.py computes concordance, NRD, no-call rate, per-class and per-MAF
sensitivity/specificity/precision/F1 vs NYGC 30x and GIAB HG001, replicate concordance,
systematic/allele-swap site errors, per-chip batch table and duplicate detection.
Cloud userdata can skip the Omni2.5 archive (OMNI=0).

scripts/cloud/trial.sh

@@ -64,7 +64,9 @@ launch)
   git archive --format=tar.gz -o /tmp/simurg-repo.tar.gz HEAD
   $AWS s3 cp /tmp/simurg-repo.tar.gz "s3://$BUCKET/$RUN/repo.tar.gz" --only-show-errors
   [[ -f scripts/cloud/tasks/$TASK.sh ]] || { echo "unknown TASK $TASK"; exit 2; }
+  OMNI=${OMNI:-1}  # 0: the task does not need the 107 GB Omni2.5 archive
   sed -e "s/__BUCKET__/$BUCKET/" -e "s/__RUN__/$RUN/" -e "s/__MAX_MINUTES__/$MAX_MINUTES/" -e "s/__TASK__/$TASK/g" \
+    -e "s/__OMNI__/$OMNI/" \
     scripts/cloud/userdata.sh > /tmp/simurg-userdata.sh
   AMI=$($AWS ssm get-parameter --name /aws/service/canonical/ubuntu/server/24.04/stable/current/arm64/hvm/ebs-gp3/ami-id \
     --query Parameter.Value --output text)