Add self-destructing AWS trial and large-scale P1 validation script

scripts/cloud/trial.sh launches one spot instance that validates the
parsers on the 1000 Genomes Omni2.5 set (2141 samples, vendor GTCs)
streamed from the public S3 bucket, uploads the summary and terminates
itself. Cost guards: spot price cap, hard time limit (shutdown =
terminate), EXIT-trap shutdown, CloudWatch idle alarm that terminates
from outside, disk deleted with the instance, monthly budget alert, and
an `audit` command listing anything still billable.

scripts/validate_p1_large.py compares every GTC with BeadArrayFiles,
checks byte-identical round-trips, IDAT pairs and BPM/EGT/CSV.

.gitignore

@@ -16,3 +16,5 @@ __pycache__/
 .ruff_cache/
 # rust
 target/
+.trial-last
+results/