Clarify dashboard sidebar item is not tab switch control

app.py

@@ -83,10 +83,6 @@ footer { display: none !important; }
   pointer-events: auto !important;
 }
 
-.nav-item[role="button"] {
-  cursor: pointer;
-}
-
 #hidden-export, #hidden-status {
   max-width: 1180px;
   margin: 0 auto 18px auto;
@@ -798,7 +794,7 @@ def dashboard_html(path: Path, notice: str = "") -> str:
         <div class="nav-item">▥ TOTEM Analytics</div>
         <div class="nav-item">☷ Revision Queue</div>
         <div class="nav-item">⬡ Risk Clusters</div>
-        <div class="nav-item js-open-codex" role="button" tabindex="0" aria-label="Open Codex Extractor tab">◈ Codex Extractor</div>
+        <div class="nav-item">◈ Codex Extractor (use top tabs)</div>
         <div class="nav-item">⇩ Export</div>
         <div class="sidebar-foot">Knowledge. Structure.<br>Story. Performance.</div>
       </aside>