Address auto model review feedback

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 39119849-5c11-476e-941b-4c3574c369cf

Author: jdneo

com.microsoft.copilot.eclipse.core.test/src/com/microsoft/copilot/eclipse/core/lsp/CopilotLanguageClientTests.java

@@ -39,6 +39,7 @@
 import com.microsoft.copilot.eclipse.core.FeatureFlags;
 import com.microsoft.copilot.eclipse.core.chat.service.IChatServiceManager;
 import com.microsoft.copilot.eclipse.core.chat.service.IReferencedFileService;
+import com.microsoft.copilot.eclipse.core.events.CopilotEventConstants;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ConversationCapabilities;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ConversationContextParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.CurrentEditorContext;
@@ -151,7 +152,6 @@ void testOnDidChangePolicy_publishesAutoModelPolicyEventOnlyWhenValueChanges() t
         .get(IEventBroker.class);
     assertNotNull(eventBroker);
 
-    String autoModelPolicyTopic = "com/microsoft/copilot/eclipse/POLICY/AUTO_MODEL_ENABLED";
     CountDownLatch eventReceived = new CountDownLatch(1);
     CountDownLatch duplicateEventReceived = new CountDownLatch(1);
     AtomicInteger eventCount = new AtomicInteger();
@@ -164,7 +164,7 @@ void testOnDidChangePolicy_publishesAutoModelPolicyEventOnlyWhenValueChanges() t
         duplicateEventReceived.countDown();
       }
     };
-    eventBroker.subscribe(autoModelPolicyTopic, eventHandler);
+    eventBroker.subscribe(CopilotEventConstants.TOPIC_DID_CHANGE_AUTO_MODEL_POLICY, eventHandler);
 
     DidChangePolicyParams params = new Gson().fromJson("""
         {

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

@@ -295,9 +295,9 @@ private void validateAndSetActiveModelForMode(Map<String, CopilotModel> modelsFo
         && modelsForCurrentMode.containsKey(currentActive.getModelKey());
     if (currentActive == null || !isCurrentModelAvailable) {
       // Try to restore user's preferred model if it's available in current mode
-      String restoredModelId = restoreActiveModel();
-      if (restoredModelId != null && modelsForCurrentMode.containsKey(restoredModelId)) {
-        ensureRealm(() -> activeModelObservable.setValue(modelsForCurrentMode.get(restoredModelId)));
+      String restoredModelKey = restoreActiveModel();
+      if (restoredModelKey != null && modelsForCurrentMode.containsKey(restoredModelKey)) {
+        ensureRealm(() -> activeModelObservable.setValue(modelsForCurrentMode.get(restoredModelKey)));
         return;
       }
       CopilotModel replacementModel = selectReplacementModel(modelsForCurrentMode);
@@ -359,20 +359,11 @@ private void onDidCopilotStatusChange(CopilotStatusResult copilotStatusResult) {
   public void setActiveModel(String modelName) {
     Map<String, CopilotModel> currentModels = modelObservable.getValue();
 
-    // Find model by model name and get its composite key
-    String compositeKey = null;
-    final CopilotModel model;
-    CopilotModel foundModel = null;
-
-    for (Map.Entry<String, CopilotModel> entry : currentModels.entrySet()) {
-      if (entry.getValue().getModelName().equals(modelName)) {
-        compositeKey = entry.getKey();
-        foundModel = entry.getValue();
-        break;
-      }
-    }
-    model = foundModel;
-    if (model != null && compositeKey != null) {
+    final CopilotModel model = currentModels.values().stream()
+        .filter(candidateModel -> candidateModel.getModelName().equals(modelName))
+        .findFirst()
+        .orElse(null);
+    if (model != null) {
       // Persist asynchronously to avoid deadlock: persistUserPreference() calls
       // persistence().get() which blocks waiting for the LSP listener thread.
       // If called on the UI thread while the listener is in syncExec, both threads