Address Alex's code review comments

core/lib/dal/src/tee_proof_generation_dal.rs

@@ -65,6 +65,11 @@ impl TeeProofGenerationDal<'_, '_> {
         let processing_timeout = pg_interval_from_duration(processing_timeout);
         let min_batch_number = i64::from(min_batch_number.0);
         let mut transaction = self.storage.start_transaction().await?;
+
+        // Lock rows in the proof_generation_details table to prevent race conditions. The
+        // tee_proof_generation_details table may not have corresponding entries yet if this is the
+        // first time the query is invoked for a batch. Locking rows in proof_generation_details
+        // ensures that two different TEE prover instances will not try to prove the same batch.
         let batch_number = sqlx::query!(
             r#"
             SELECT