Vendor the canonical CTO v1 Draft 2020-12 schema with its import descriptor. Add the isolated rust-release-manifest workspace library and CLI for real JSON Schema validation, live semantic binding, deterministic rendering, and complete five-file payload classification. Add make check-rust-release-manifest to make ci with fixture, MANIFEST, and RELEASE_DIR modes while leaving the observer binary dependency graph unchanged. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>