[ITSGJY]

Summary

Fix Runner Job admission for Node project_build so a build planned from a Project's declared npm, pnpm, yarn, or bun manager is admitted under the same canonical process/digest contract as the typed Build Plan.

• Reuse ProjectBuildPlan::is_valid() at the Runner Job admission boundary, aligning it with Core wire validation and the Runner-owned planner.
• Preserve exact command shape, invocation digest, current manifest/lockfile provenance, queued-source revalidation, and the existing Job/Runner authority model.
• Add a deterministic no-child regression for all four managers with both explicit adapter=node and adapter=auto, including typed wire decode, Job queue admission, and a manager substitution with a recomputed digest rejected by the source fence.

The previous admission validator rebuilt the canonical command with an npm-defaulting helper. A valid pnpm/yarn/bun plan thus passed Runner planning and Core validation but was rejected before Job enqueue. The Runner's current Project recipe remains authoritative for manager selection.

Verification

• RED (original main@7b35aafb): The new regression fails on pnpm/Node: Runner rejected its own canonical Node build plan.
• GREEN (commit ed5afe29): The identical regression passes, including all eight manager/adapter combinations.
• Focused Runner project_build suite: 25 passed, 0 failed, 1 ignored (real Node/npm fixture).
• Ran the existing ignored real Node/npm build fixture separately: 1 passed.
• cargo fmt --all -- --check and git diff --check passed.
• Independent read-only Codex review: no P1/P2 findings.
• Fork GitHub Actions CI on exact commit ed5afe29eaa2c86e11aaa3b906cb6d3b0959a2f2: Success — 13 jobs passed, 0 failed, 5 correctly skipped by path-based selection (run 39567710526). Linux Runner/Server/workspace, Windows Runner, macOS Core, Contracts, MCP conformance, and the CI test gate passed.

Scope

Only the Runner admission check and its adjacent regression tests change (2 files). No new model-facing tool, schema/capability, executable-selection rule, process fallback, or persistence/retry contract. This follows the existing project-operation lifecycle tracked in #962.