feedback5 WB: the data of 补位 and 自选 — chess.json keeps the official backup fields, data/backups.json builds the 17 stand-ins and the DIY picks

chess.json: every record carries the shop row's backupCharId / backupTmplId / backupCharSkillIndex /
backupCharUniEquipId / backupCharPotRank verbatim as `backup` (both forms; nothing else changed).
data/backups.json: units = the 17 原型干员 with a form per status they fight at (43 forms: stats, trait,
talents, every unlocked skill, modules), diy = the 4 slots, the prototype picks per tier (9 6★ at 5 and 6,
six 4★ at 5), the 78 owned-6★ picks and their faction bonds (mainPower + subPower vs powerIdList, else 协防).
shared/standIn.js composes a stand-in (or a DIY prototype) into a chess-shaped record; the build fails when
the form builder cannot give back every PRESET chess field for field. test/backups.test.js (10 tests).

test/data.test.js

@@ -24,7 +24,7 @@ const CACHE = join(ROOT, '.cache', 'gamedata');
 const HAS_CACHE = ['excel/activity_table.json', 'excel/character_table.json', 'excel/skill_table.json', 'excel/battle_equip_table.json',
   'levels/enemydata/enemy_database.json', 'levels/activities/act1autochess/level_autochess_enemy_data.json']
   .every((rel) => existsSync(join(CACHE, rel)));
-const FILES = ['config', 'chess', 'bonds', 'garrisons', 'items', 'bands', 'effects', 'choices', 'enemies', 'factions', 'waves', 'stages', 'bosses', 'tokens'];
+const FILES = ['config', 'chess', 'bonds', 'garrisons', 'items', 'bands', 'effects', 'choices', 'enemies', 'factions', 'waves', 'stages', 'bosses', 'tokens', 'backups'];
 
 /** Load one data file (fails with a helpful message when the build has not run). */
 function load(name) {