fix: handle missing API key in getActiveProviderWithKey function

- Added a check to return null if the API key is not available, improving error handling in AI provider integration.

Author: Skeptic-systems

apps/desktop/src/lib/aiClient.ts

@@ -93,6 +93,7 @@ export async function getActiveProviderWithKey(
 
   try {
     const apiKey = await getAIApiKey(config.provider);
+    if (!apiKey) return null;
     return { provider: config.provider, apiKey };
   } catch {
     return null;