Validate omitted GGUF strings without materializing discarded text while preserving full UTF-8 checks and retained Evidence. Record real-model costs and workflow coverage; preserve failed experiment receipts through cleanup.
Fixes#5774.
Reuse the format owner's full validation for exact authenticated immutable captures across retained queries. Preserve ordinary mutable-input validation and per-request subject, coverage and budget checks.
Refs #3133.
Co-authored-by: Kaoru0822 <208281322+kaoru0822-kitauji@users.noreply.github.com>