feat: high-concurrency userid hashing

utils/export_regions.py

@@ -1,7 +1,8 @@
 import polars as pl
-
-from helpers import salted_hash_userid
+import polars_hash as pl_hash
 
 pl.scan_parquet("regions.parquet").with_columns(
-    pl.col("user_id").map_elements(salted_hash_userid, return_dtype=pl.String)
-).collect().write_parquet("regions_pub.parquet")
+    pl.col("user_id").cast(pl.String).add("Lt2N5xgjJOqRsT5qVt7wWYw6SqOPZDI7")
+).with_columns(pl_hash.col("user_id").chash.sha2_256()).collect().write_parquet(
+    "regions_pub.parquet"
+)