Fix llm queries (#16006)

Release Notes:

- N/A

---------

Co-authored-by: Marshall <marshall@zed.dev>

Procfile.postgrest

@@ -0,0 +1,2 @@
+app: postgrest crates/collab/postgrest_app.conf
+llm: postgrest crates/collab/postgrest_llm.conf

crates/collab/postgrest_app.conf

@@ -0,0 +1,4 @@
+db-uri = "postgres://postgres@localhost/zed_llm"
+server-port = 8082
+jwt-secret = "the-postgrest-jwt-secret-for-authorization"
+log-level = "info"

crates/collab/src/llm/db/queries/usages.rs

@@ -173,12 +173,16 @@ impl LlmDatabase {
 
             let users_in_recent_minutes = usage::Entity::find()
                 .filter(usage::Column::Timestamp.gte(minute_since.naive_utc()))
+                .select_only()
+                .column(usage::Column::UserId)
                 .group_by(usage::Column::UserId)
                 .count(&*tx)
                 .await? as usize;
 
             let users_in_recent_days = usage::Entity::find()
                 .filter(usage::Column::Timestamp.gte(day_since.naive_utc()))
+                .select_only()
+                .column(usage::Column::UserId)
                 .group_by(usage::Column::UserId)
                 .count(&*tx)
                 .await? as usize;