Dyalog 18.0 namespace path resolution change and cross-session workspace object caching

Context

The namespace path resolution hierarchy was restructured between Dyalog 17.0 and 18.0, altering how ⎕NS and ⎕ML reference cached workspace objects across sessions. This change creates a compatibility boundary for applications that persist class definitions or workspace objects between major version upgrades.

Goal

Determine whether the 18.0 path resolution rules invalidate previously cached class definitions created via ⎕WC when a workspace is loaded in a new major version, and whether explicit ⎕CR cleanup is required to avoid stale references.

Constraints

• Behavior must be verified against documented 17.0→18.0 transition semantics, not inferred from release notes alone.
• Core edition lacks certain ⎕FSE primitives, so file-based cache validation may differ between editions.

Questions

1. Does loading a 17.0-saved workspace in 18.0 automatically refresh ⎕WC-created class metadata, or does stale session-state metadata persist until explicit ⎕CR?
2. How does the revised ⎕NS/⎕ML resolution order interact with cross-session object caches when both editions are deployed in the same environment?