Delete OAuth application

Rate limit: 60 requests per 60 seconds. This is the default shared quota — it is shared with every other endpoint that has no dedicated limit, so requests across those endpoints all draw from the same budget.

Permanently deletes an OAuth application. Only the application's admin can delete it. Non-admins receive 404 Not Found (opaque authorization). The application disappears from GET /api/v1/sso/applications after the next cache refresh cycle.