```html
<section id="sidebar-audit">

  <h2>Sidebar Audit — Crystal–Mycelial Engine</h2>

  <!-- Navigation Integrity -->
  <div class="audit-block">
    <h3>Navigation Integrity</h3>
    <ul>
      <li>Front Door: OK — index.html present</li>
      <li>Regime Pages: OK — BGR, HRR, MLR present</li>
      <li>Reference Pages: OK — operator_mapping, envelopes_reference, glossary, flow diagram</li>
      <li>Substrate Pages: OK — structural_overview, substrate_swap, calibration_as_structure</li>
      <li>Metadata Pages: OK — head_block, session_context, diff tables, sitemap entry, validator report</li>
    </ul>
  </div>

  <!-- Phantom Entry Check -->
  <div class="audit-block">
    <h3>Phantom Entry Check</h3>
    <ul>
      <li>/docs/rtt/Crystal_Mycelial_Engine/docs/regime_flow_diagram.txt — OK</li>
      <li>/docs/rtt/Crystal_Mycelial_Engine/structural_overview.png.txt — OK (text wrapper)</li>
      <li>/docs/rtt/Crystal_Mycelial_Engine/docs/substrate_swap.md — OK</li>
      <li>/docs/rtt/Crystal_Mycelial_Engine/docs/calibration_as_structure.md — OK</li>
      <li>No phantom or missing sidebar entries detected</li>
    </ul>
  </div>

  <!-- Metadata Presence -->
  <div class="audit-block">
    <h3>Metadata Presence</h3>
    <ul>
      <li>Canonical head block: OK</li>
      <li>Session context: OK</li>
      <li>Diff tables: OK</li>
      <li>Sitemap entry: OK</li>
      <li>Validator report: OK</li>
    </ul>
  </div>

  <!-- Regime Flow Consistency -->
  <div class="audit-block">
    <h3>Regime Flow Consistency</h3>
    <ul>
      <li>BGR → HRR → MLR sequence: OK</li>
      <li>Envelope transitions: OK</li>
      <li>Operator emphasis by regime: OK</li>
      <li>Substrate transitions (bio → hybrid → mineral): OK</li>
    </ul>
  </div>

  <!-- Module Health Summary -->
  <div class="audit-block">
    <h3>Module Health Summary</h3>
    <p>All sidebar-linked CME documentation is present, canonical, and internally consistent. No drift detected.</p>
  </div>

</section>
```