feat: complete durable artifact lifecycle

[bitgorust]

What changed

• Add crash-safe, cross-process artifact publication.
• Add stable artifact identity, immutable revision history, migration, rollback, archive, import, and export.
• Add CAS-protected state with bounded limits and lifecycle CLI/plugin surfaces.
• Retain the approved optional macOS and Windows native/WSL evidence boundary.

Why

Goal 2 requires durable local artifact history and recovery before renderer and host work can rely on artifact identity.

User impact

Users can address artifacts by stable identity, update safely, inspect history, restore auditable revisions, migrate legacy stores, and recover from interrupted writes.

Validation

• Node 24 build passes.
• The 214-test suite passes at the stacked Goal 3 head.
• All 35 structural checks pass.
• Goal 2 packets are archived with Ubuntu/ext4 and Chromium workflow evidence.

This is the draft stacked foundation for the Goal 3 PR.