Design runtime event adapters for GC and managed runtimes

[itdevwu]

Goal

Expose bounded CPython runtime boundaries only when the target binary advertises a verified attachable source.

Acceptance criteria

• Validation discovers SystemTap/DTrace notes from the mapped CPython executable or libpython instead of assuming a Python-version ABI.
• The first supported adapter covers gc__start and gc__done with exact lifecycle semantics and versioned scalar metadata.
• Missing probes, disabled semaphores, unsupported argument layouts, and target changes fail explicitly.
• Pointer-referenced strings, Python objects, environments, and heap contents are not collected by default.
• Function entry/return support is exposed only for builds whose actual notes and bounded payload contract pass a release matrix; it is not a fallback promise.
• Live fixtures cover a probe-enabled system Python and a Python build without markers.