[P1] Publish operator-facing runtime reconciliation summary

[a-a-k]

Context

Runtime reconciliation avoids deleting topology solely because a window is quiet, but operators need a compact explanation of what changed, what was retained, and why downstream consumers should trust the latest artifact.

Scope

Expose a human-readable operator summary for reconciliation decisions in addition to the existing machine-readable report surface.

Definition of Done

• Runtime output or docs summarize retained, stale, and retired entities.
• The summary explains how telemetry health affects retention and confidence.
• The existing machine-readable reconciliation report remains available for automation.
• Tests or fixtures cover retained, stale, retired, and telemetry-health-damped cases.