chore: add some more debug logs (#1979)

P99 is usually <100ms which is excellent, but occasionally has big
spikes to 1000ms. This is only on the record index.

I don't want this to get out of hand. I've ran a few test queries and
they all complete very fast, and are purely index scans.

Hopefully this helps figure out if it's a specific user with tonnes of
stores or something? Otherwise there could be something up with my db.

I should probably also figure out some proper log levels or tracing lol.

crates/atuin-server/src/handlers/v0/record.rs

@@ -70,6 +70,8 @@ pub async fn index<DB: Database>(
         }
     };
 
+    tracing::debug!(user = user.username, "record index request");
+
     Ok(Json(record_index))
 }