- simdata: DataSource keeps `backups` (rawBackups follows the fallback chain); getStandIn = shared/standIn.js standInRecord normalised (the chess's ids / bonds / 特质 / tier, the stand-in's body, def.standInFor); a PRESET / DIY chess or a source without backups fields itself; the per-battle view maps id-only lookups. - spec.js keeps `standIn` only when exactly true (never on a token); Battle passes it to getChess; syncUnitLoadout carries it; UnitInfo `standInFor`. - content/index.js kitOf: a stand-in's kit is KITS[def.charId] only; no default skill (a stand-in kit writes `skills`); without a kit the generic kit plus genericTalents. kits/index.js STANDIN_KIT_FILES / STANDIN_KITS, merged after the tier groups (old keys keep their order; golden unchanged). - server/data.js and tools/setup.mjs expect backups.json. - test/content/standin.test.js: the plumbing and the eight 预备干员 on all 28 chess records they replace.