Task 1.2 (Req 2.1, 2.3, 2.5).
- semantic/obligations/shapes.py: ObligationShape (family obligation,
text-free key), derive_obligation and explain_skip. The lesson is any
discharged operation of the target's walker-visible kind, fixed side
first and then the vulnerable function's own safe branch, since
Real-Vuln twins are flag-toggled identical functions or unrelated trap
functions; keyword constraints are read from the call's source line
(positional-only IR call sites); an identity constraint bound from the
request or a constant discharges nothing.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
