[ITSGJY]

Fork-only CI staging for commit 2d717ab6e9b0c84bb21c7e8166d973b25b8ecd79, based on upstream d11cdd226abd1efdb0351d4b58d502acb8f41f6e.

Validates the yyjeqhc#599 F2 slice:

• one shared portable project-operation package scope is the source of truth for project_build and project_validate
• existing ProjectBuildScope / ProjectValidationScope Rust API names remain available
• model JSON/MCP schema stays scope: { packages: [...] } with the same bounds and closed-object behavior
• operation-specific validation errors remain unchanged
• canonical argv, provenance/digests, Runner capabilities, admission, and fences are unchanged

This PR is fork-only CI staging. Upstream submission is intentionally deferred until predecessor yyjeqhc#807 is actually merged into upstream main.