Add bounded teacher guidance action card

[alexdancer]

Summary

• replace the Evidence Desk opener surface with the captain-selected Variant B teacher decision map
• persist a complete six-field card with deterministic follow-up/listen support and a manual-synthetic-only three-field AI draft
• add bounded-packet validation, cause-specific fallback, migration, focused tests, and aligned contracts/docs

Validation

• npm test
• npm run typecheck -- --pretty false
• npm run lint -- --quiet
• npm run check:determinism
• npm run build
• npm run eval:portfolio
• RUN_DB_TESTS=1 node --env-file=.env node_modules/vitest/vitest.mjs run packages/db/test