refactor: split validator-utils.ts (2646 lines) into topic-scoped modules

Found during v0.11.0-beta.1 release review (Tech Lead). `packages/opencode/src/altimate/validators/validator-utils.ts` is a 2646-line grab-bag: JSON envelope parsing, dbt YAML path resolution, deliverable-token extraction, run_results interpretation, Jinja `{% if %}` scanning, SQL comment/literal/Jinja masking, and telemetry sanitization all in one file with no internal seam. Well-tested but hard to extend. Deferred because: a real split (jinja.ts / sql-sanitize.ts / telemetry-sanitize.ts / dbt-project.ts), not a 30-min fix.