TypedPython: virtual objects, refcount elision and region allocation (SPEC N-12) #143

User instruction (2026-10-03): go further toward Rust while guaranteeing CPython identity. Design: docs/design/typedpython.md §4.3.4, SPEC N-12.

Blocked on a user decision: whether garbage-collection timing is part of the identity (§4.3.4 마.1).

Done when, after the decision: binary-trees builds its tree as virtual objects in a region, the verifier proves the four N-12 properties, the differential observation tests (id, gc.get_objects count and order, gc.get_referrers, getrefcount, tracemalloc, is, MemoryError) equal the interpreter, and the mutation tests fail as described.