Review round 1 validation (fresh isolated evidence)

Environment for every command:
  env -u PI_SUBAGENT_CHILD -u PI_GOALS_ROLE PI_GOALS_EVIDENCE_DIR=/tmp/pi-goals-review-round-1-evidence

npx vitest run test/goals-flow.test.ts test/intercom.test.ts test/supervisor-session.test.ts
  PASS: 3 files, 81 tests.

npm run typecheck
  PASS: tsc --noEmit.

npm run lint
  PASS: biome check src/ test/ (42 files; no fixes).

npm run build
  PASS: tsc.

npm test
  PASS: 22 files, 159 tests.
  Note: `fatal: not a git repository` is expected stderr from a negative preflight regression.

git diff --check
  PASS.
