fix(docker): the MySQL test stack stores the sample emoji text as mojibake #1823

Problem

docker/mysql/init seeds all_mysql_types.col_text with Long multiline text paragraph with emoji 🚀 ðŸ¬: the stored bytes are the double-encoded form (C3B0 C5B8 C5A1 E282AC …), so the grid shows mojibake and cannot be used to check Unicode handling. The column is utf8mb4; the init script was read as latin1 by the client (mysql without --default-character-set=utf8mb4).

Fix

Put SET NAMES utf8mb4; at the top of the init SQL (or pass --default-character-set=utf8mb4) and re-seed (docker compose down -v). Same check for the MongoDB and ClickHouse seeds.