Seven-task plan spanning two worktrees: Phase 1 (local-dev) for SKILL.md instrumentation (pilot tdd, then rollout to 6 binary-outcome skills), Phase 2 (hyperguild) for the /pass-rate endpoint + CLI subcommand. Uses GET for the pure-read endpoint (REST semantics) despite the brain API's POST-everywhere precedent for legacy endpoints. Pilot-then-rollout structure: tdd SKILL.md lands first; the endpoint TDD task naturally exercises the new logging contract as the dogfood validation step before the other 6 skills get instrumented.