Phase 0 of epic #1507. Records the decision to make the Runtime Artifact
Conversion Module the single owner of per-runtime content rewriting, flip the
dependency direction to installer/layout -> conversion, and close the
surface.cts -> bin/install.js getInstallExports relay. Doc-only.
Resolves ADR-3660 Initial-Scope deferral; distinct from epic #1258.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0187qgypdy1wkWRpdaf2hRuD
