Task 1.1 (Req 2.1-2.4). Spec approved by the maintainer in session.
- semantic/variants.py: Shape (language, sink trailing name, arity,
source positions and kinds, closed guard kind, mechanism id) with a
stable text-free key; derive_shape finds the labeled sink call site in
the vulnerable FileIR, traces argument identifiers through binds to a
fact source, a parameter or a container read, and classifies the guard
the fixed side added from the labeled function's added statements
against a closed set (none when unknown). No path, line or literal
enters a shape; a constant-only call teaches nothing.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG