fix: refine Patient Zero cleaner guidance

[christopherjnelson]

Summary

• treat occupied blocked cleans as successful historical defense rather than a reason to vacate
• distinguish historical event cells from the cleaner's live position and prohibit delayed chase or evacuation advice
• make cleaner broadcasts selective and non-repeating
• prefer named alliance reinforcement under sustained pressure
• allow bounded pressure-pattern memory without per-event logging
• preserve the existing high-value TARGET/ACTION/REASON and no-filler coordinator contract

Validation

Repository owner confirmed the following local validation is green:

• pnpm format
• pnpm --filter @hexzero/agent-runtime test
• pnpm validate
• pnpm test:e2e

Scope

Prompt policy, focused tests, and documentation only. No engine, schema, feed, UI, or provider-call changes. Follow-up to merged PR #41 after experiment review.