Non-Functional Delta: YU09-ops-hardening over YU08-execution-algo-engine

Req	Status	Notes
NFR-OH01 no throughput regression with archival disabled	Done	bench-compare against the YU08 baseline, journal.archive.enabled=false (the shipped default).
NFR-OH02 GCS upload off the journaler thread	Done	JournalArchiver runs its own single-thread ExecutorService; archiveAsync only submits, never blocks the caller.
NFR-OH03 no Secret value committed	Done	All three Secrets created via kubectl create secret per quickstart.md; .gitignore/repo hygiene unaffected since nothing is written to a tracked path.
NFR-OH04 required vs. optional Secrets	Done	mariadb-credentials/auth-secrets have no optional: true; pods block on CreateContainerConfigError until created, same as any other required config. order-matcher-journal-gcs-hmac is optional: true.