Two sections, forged the same way as git-operations.md: input
contract discipline (degenerate input as the default case,
validate/sanitize/reject as distinct responses, the
meaning-preserving line for when sanitizing is safe) and
failure-propagation discipline (never substitute a plausible
artifact for a failed operation, retry/abort/surface, one
signaling convention per boundary, the anti-pattern catalogue).
Environment/verification parity was scoped out deliberately —
different axis (confidence-establishment, not code behavior),
earns its own handbook later rather than a section here.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011EBCcjJvEvhpToahqdsLLA
mikkeli