feat: hide usage tracking UI when API key is configured

Usage tracking via CLI only works for Claude Code subscription users.
Hide the Usage button and settings section when an Anthropic API key is set.

apps/ui/src/components/views/settings-view.tsx

@@ -47,8 +47,12 @@ export function SettingsView() {
     defaultAIProfileId,
     setDefaultAIProfileId,
     aiProfiles,
+    apiKeys,
   } = useAppStore();
 
+  // Hide usage tracking when using API key (only show for Claude Code CLI users)
+  const showUsageTracking = !apiKeys.anthropic;
+
   // Convert electron Project to settings-view Project type
   const convertProject = (
     project: ElectronProject | null
@@ -99,7 +103,7 @@ export function SettingsView() {
               isChecking={isCheckingClaudeCli}
               onRefresh={handleRefreshClaudeCli}
             />
-            <ClaudeUsageSection />
+            {showUsageTracking && <ClaudeUsageSection />}
           </div>
         );
       case "ai-enhancement":