INT-OBJECT-01R: Correct native checking callable reflection #277

Scope

Correct the callable identities and unbound names of the adopted native type.instancecheck/subclasscheck helpers. Pinned CPython 3.14.7 exposes unbound method_descriptor values, bound builtin_function_or_method values, bare name and type-qualified qualname. The current helpers report generic builtin/method-wrapper identities and qualified names in name.

Acceptance

Add a finite source/reference matrix for unbound/bound helper identity, alias stability, adopted type relations, canonical metadata and explicit construction refusals. Keep invocation, descriptor binding, native ancestry and class/core admission unchanged. Verify Node/Chromium drain/step, collection, offline new-source behavior and updated payload/source hashes. Preserve the eight composed resource observations.

Parent: #123. Depends on #272; focused stacked work is allowed. No new dependency, host grant, publication or deployment.