feat(doctor+docs): add archive health checks and Discord memory runbook #81
Description
Parent epic: #74
Objective
Add health diagnostics and docs for archive+recall operations.
Required Changes
- Doctor checks for archive state, index integrity, and staleness.
- Runbook covering tuning, recovery, and expected behavior.
- Clear guidance on Discord data retention/privacy implications.
TDD Gates
- Doctor unit tests for pass/warn/error cases.
- Integration test where broken index is detected and reported.
- Docs checklist for fresh install + upgrade + recovery paths.
Acceptance Criteria
- Failures are discoverable with actionable remediation.
- Operators can tune for cost/quality tradeoffs safely.