docs(mcp): Update v0.app setup path to current UI

The v0.app MCP flow moved — the registry is now under
Account Settings → Integrations → MCP Connections, and users search the
catalog for the Sentry brand entry rather than picking a configured key.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: rahulchhabria

docs/ai/mcp.mdx

@@ -337,7 +337,7 @@ Open the MCP menu with `/mcp` → `Add MCP Server from Registry` → search for
 
 <Expandable title="Setup Instructions" group="clients">
 
-In the [v0.app](https://v0.app) UI: `Prompt Tools` → `Add MCP` → select sentry.
+In the [v0.app](https://v0.app) UI: `Account Settings` → `Integrations` → under **MCP Connections** click `Add MCP` → search for Sentry.
 
 </Expandable>