feature request: Create user exist endpoint #7525
Description
What problem did you meet?
In our microservice setup, every time a new domain entity is created we must first validate that the referenced user ID actually exists. In most cases one user is creating a record that points to a different user, so we can’t rely on the target user’s access-token to perform the lookup. Right now the only way to do the validation is to fetch the entire user profile from the User Service. That profile payload is large, the query is slow, and the extra network hop multiplies the latency of every write operation across the system.
Describe what you'd like Logto to have
A lightweight request that returns nothing more than an “exists / doesn’t exist” flag for a given user ID. This minimal check would cut superfluous traffic, keep data exposure to a minimum, simplify caching, reduce end-to-end latency, and remove brittle dependencies on the full user‐object schema.