Memory consolidation can mis-handle reusable artifacts and hide blocking-task failures

Observed while reviewing downstream carry of recent memory-consolidation changes.

Summary
Phase 2 memory consolidation can conflate a usable no-op / reuse case with an invalid artifact state, and the artifact-state loader can also collapse blocking-task failure into the same effective path as missing artifacts.

Why this matters

• valid phase-2 reuse/no-op paths should be able to succeed when the retained memory workspace already has usable artifacts
• blocking-task failure is a different failure mode from missing artifacts and is easier to diagnose if it stays distinct