feat: Implement audience-only secret badge for Twenty Sprouts game

feat: update agent personas and scheduling in YAML configurations; enhance event handling and memory deduplication in core logic

feat(observability): instrument models, conductor, memory, ledger (Units 2-6)

feat: implement streaming agent responses and enhance conversation flow with repeat guards

feat(core): add resilient loop and shared blackboard

Refactor code structure for improved readability and maintainability

feat: phase 2 architecture — manifest system, structured output, salience memory, SQLite ledger, observer

feat: phase 1 — memory layer, governor, second scenario, 70 passing tests