Address comments.

Co-authored-by: Copilot <copilot@github.com>

Author: ethanyhou

com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/ChatAssistProcessor.java

@@ -125,7 +125,8 @@ public ICompletionProposal[] createCopilotCompletionTemplateProposals(String pre
     String lowerPrefix = prefix.toLowerCase();
 
     // Sort results by match quality, then build proposals.
-    return Arrays.stream(templates).map(t -> new SimpleEntry<>(t, getMatchPriority(t, lowerPrefix)))
+    return Arrays.stream(templates).filter(t -> StringUtils.isNotBlank(t.id()))
+        .map(t -> new SimpleEntry<>(t, getMatchPriority(t, lowerPrefix)))
         .filter(e -> e.getValue() >= 0).sorted(Comparator.comparingInt(Entry::getValue)).map(e -> {
           ConversationTemplate t = e.getKey();
           boolean isSkill = t.source() == TemplateSource.SKILL;

com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/services/ChatCompletionService.java

@@ -255,6 +255,9 @@ public void dispose() {
     this.authStatusManager.removeCopilotAuthStatusListener(this);
     ResourcesPlugin.getWorkspace().removeResourceChangeListener(skillFileListener);
     CopilotUi.getPlugin().getLanguageServerSettingManager().unregisterPropertyChangeListener(preferenceListener);
+    if (this.eventBroker != null && this.customPromptsChangedHandler != null) {
+      this.eventBroker.unsubscribe(this.customPromptsChangedHandler);
+    }
   }
 
   /**