feat: store each named pet's LOT in pet_names

pet_names gets a pet_lot column (mysql 80, sqlite 63). The world writes
it whenever it saves a pet name, from the pet entity's LOT, and fills it
in for older rows when the owner loads into a world (from the pets the
game loads for that character, only where it is still missing).

The dashboard's pet name tables read pet_lot instead of scanning the
owner's character XML; pets without it yet show as Unknown.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

migrations/dlu/sqlite/63_pet_name_lot.sql

@@ -0,0 +1,2 @@
+/* Which kind of pet (its LOT) each named pet is. See the MySQL migration. */
+ALTER TABLE pet_names ADD COLUMN pet_lot INTEGER NULL DEFAULT NULL;