Replacing or deleting a class getter property does not mutate the object it would return. Apply the existing object-accessor write boundary to instance and static getters.
Validation: source mutation regressions and compiled CLI/stdio MCP acceptance preserve literal 1 for all four assignment/deletion cases; check:fast passes.
Follow object, instance, and static getter results when invalidating shared values. Respect descriptor replacement, known spread overrides, inheritance alternatives, and unresolved computed keys. Preserve conservative uncertainty for fresh getter results and verify shared mutations through CLI and MCP.
Fixes#1494