feedback5: merge W5G — 补位 end to end: the 干员持有 tab (drop NORMAL chess), room.ownership, stand-ins in every field, 「替补：X」 badges, the stand-in's body on the board and detail card, golden standins family

Golden regenerated on the merged code (the textual merge had no conflict and equals the regenerated files): against feedback5 only the new match coop2-NORMAL-14-standins and the new standins.json (10 battles); against fb5-standin-game exactly the W5F and W5J scenarios (roster-001/002/007/009/016/026/027/028/038/040/041/042/044, bond-egirShip-low / siracusaShip-high / suntShip-high, boss-boss_2-pair / boss_6-pair, solo-NORMAL-1, coop2-NORMAL-3, coop3-ABYSS-5, coop4-FUNNY-6, coop2-NORMAL-8-serverrun); standins unchanged. test/match 536/536, the stand-in / golden / docs suites 175/175.

server/sim/content/kits/README.md

@@ -104,8 +104,11 @@ export default {
 A NORMAL chess whose operator the player does not own fights as its official stand-in (原型干员, data/backups.json,
 docs/DATA.md §18): the chess's ids, bonds, 特质, tier and price, the stand-in's body — stats, range, trait, talents, the
 skill `backup.skillIndex` and the module `backup.uniEquipId` the chess names. The sim gets that def from
-`battle.data.getChess(chessId, { standIn: true })` (a PlayerBattleInput entry with `standIn: true`); `def.charId` is the
-stand-in's, `def.standInFor` the replaced operator's charId.
+`battle.data.getChess(chessId, { standIn: true })` (a PlayerBattleInput entry with `standIn: true` — in a match, the
+player's chess marked 未持有 on the 干员持有 tab, `PlayerState.battleInput`); `def.charId` is the stand-in's,
+`def.standInFor` the replaced operator's charId. The golden `standins` family (tools/golden.mjs) fields every NORMAL
+chess record as its stand-in, so a kit change that alters a battle shows there (test/golden-standins.test.js checks that
+every active backup skill is cast).
 
 - **File and key**: `ops/standin-<codename>.js`, the code name being the stand-in's charId without `char_<n>_`
   (`standin-acguad.js` = Sharp, `char_609_acguad`); the default export has exactly one key, that charId:
@@ -161,8 +164,9 @@ stand-in's, `def.standInFor` the replaced operator's charId.
 - Assert that the unit is the stand-in (`u.def.charId`, `u.def.standInFor`, `u.skill.id`) and that its kit is yours, not
   the generic one (`!u.kit.generic`); then the checklist below as for any operator. Examples:
   `test/content/standin.test.js` (the plumbing and the eight 预备干员).
-- A stand-in kit is new gameplay for stand-ins only: the golden corpus fields no stand-in, so its digests stay as they
-  are.
+- A stand-in kit is gameplay for stand-ins only: of the golden corpus only the `standins` family (and the 补位 match
+  `coop2-NORMAL-14-standins`) fields stand-ins, so a kit change moves those digests and no other — `npm run
+  golden:update`, then review that the change is confined to the battles that field the stand-in.
 
 ## The fidelity rule