Public-safe on-demand Simulator lifecycle

[VladimirBrejcha]

Summary

• make Simulator Broker own deterministic warm reuse, boot-on-acquisition, idle reconciliation, and operator controls
• add opt-in idle policy, count-only confirmed cleanup, daemon scheduling, snapshot summaries, and macOS Overview controls
• add a tracked-text public-safety scanner to the normal test and distribution gates, with an ignored local denylist

Verification

• npm test — passed: 206 broker, 120 client/service, 24 harness-adoption, and 67 macOS app tests
• npm --prefix agent-harness test — passed: 104 tests
• npm run verify:public-surface — passed: 240 tracked text files
• required implementation/spec profiles and all three agent:complete closeout gates passed

Rollout

The machine-local 300-second policy and one-time cleanup are intentionally deferred until this release is available. No host aliases, simulator identifiers, local paths, operator identities, or personalized defaults are committed.