SPIRE WorkloadAttestor that reads governance env vars from /proc/{pid}/environ
(walking up the process tree to find gsh) and emits gsap: selectors on workload
SVIDs. Maps BASCULE_* vars set by bascule-shell and future GSH_* vars to the
11-selector vocabulary defined in gsap-types/src/selectors.rs.
- pkg/gsap/selectors.go: shared Go constants mirroring Rust vocabulary
- cmd/gsap-attestor/: plugin implementation with /proc reading, process tree
walking, capability ceiling translation, and fail-open for non-governed processes
- 28 tests covering selector extraction, proc parsing, tree walking, and depth limits
- Makefile, Dockerfile, deploy config updated
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>