feat(composio): hide composio from copilot whilst the API key is not set in isSignedIn is false

- Added a function to invalidate the Copilot instructions cache when setting the API key.
- Updated the Composio tools prompt to return an empty string if Composio is not configured, simplifying the user experience.
- Refactored the Copilot instructions to conditionally include Composio-related guidance based on configuration status, improving clarity on third-party service interactions.
- Introduced a new function to build a skill catalog string, allowing for optional exclusion of specific skills, enhancing the skill management capabilities.

apps/x/apps/main/src/composio-handler.ts

@@ -44,6 +44,7 @@ export async function isConfigured(): Promise<{ configured: boolean }> {
 export function setApiKey(apiKey: string): { success: boolean; error?: string } {
     try {
         composioClient.setApiKey(apiKey);
+        invalidateCopilotInstructionsCache();
         return { success: true };
     } catch (error) {
         return {