Implements the shell side of GCAP-SPEC-SHELLBOUND-BROKER-0001.
The broker (Capstone) issues ACs. This module consumes them.
GsapClient:
authorize() — request AC, validate R-20/R-22/R-23/R-24
complete() — post CR with 3x retry (R-29)
ConsumedContextRegistry:
Filesystem-based replay prevention (R-22)
4/4 unit tests passing:
test_corpus_mismatch, test_params_modified,
test_replay_rejected, test_valid_ac
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>