fix: create user_binary row on character creation (#176)

New characters were missing their user_binary record, preventing them
from entering their house. Both sign server and API character creation
paths now insert the row. A backfill migration fixes existing databases.

server/api/repo_character.go

@@ -42,6 +42,10 @@ func (r *APICharacterRepository) Create(ctx context.Context, userID uint32, last
 		RETURNING id, name, is_female, weapon_type, hr, gr, last_login`,
 		userID, lastLogin,
 	)
+	if err != nil {
+		return character, err
+	}
+	_, err = r.db.ExecContext(ctx, `INSERT INTO user_binary (id) VALUES ($1)`, character.ID)
 	return character, err
 }