Enhance HUD dot functionality: add context validation and error handling, update member index from shared index if empty

content.js

@@ -726,6 +726,8 @@ function ensureHudDot() {
 }
 
 function updateHudDot() {
+  if (contextInvalidated || !document?.body) return;
+  try {
   const dot = ensureHudDot();
   const panel = document.getElementById(HUD_PANEL_ID);
   const total = sharedIndex.size;
@@ -745,6 +747,9 @@ function updateHudDot() {
     hudDirty = false;
     lastHudSignature = signature;
   }
+  } catch (error) {
+    contextInvalidated = true;
+  }
 }
 
 function flashHudDot() {
@@ -906,6 +911,18 @@ function loadStoredIndex() {
       data[STORAGE_KEY_MEMBER].forEach(item =>
         sharedMemberIndex.set(item.id, item)
       );
+      if (sharedMemberIndex.size === 0 && sharedIndex.size > 0) {
+        for (const item of sharedIndex.values()) {
+          sharedMemberIndex.set(item.id, {
+            id: item.id,
+            channelKey: item.channelKey,
+            channelLabel: item.channelLabel,
+            channelUrl: item.channelUrl,
+            lastSeen: item.lastSeen || Date.now()
+          });
+        }
+        schedulePersistMemberIndex();
+      }
       updateHudDot();
     }
   );