feedback5 WE1: 庇护 is one effect per unit — 宴, 余, 缪尔赛思, 赫拉格, 左乐 and 赫德雷 join the shared key (follow-up 18)

gamedata_const ba.protect / PRTS 术语 庇护 "受到的物理和法术伤害降低相应比例（同名效果取最高）": the strongest source holds; the
自选 kits already used battle.applyStrongest('protect'), these six multiplied private cuts with it.

- kits/shared/tier1.js: PROTECT, protectMods, PROTECT_TICK_HOLD and holdProtect (applyStrongest on the shared key).
- 宴 / 赫拉格 / 左乐 (below their HP threshold): refreshed every tick and at each hit on them; 余 (blocking) and 缪尔赛思's
  melee copies at their old cadence; 赫德雷's 庇护 joins the key, his CRU-X 物理伤害 + becomes its own instance. 左乐 keeps the
  PRTS S2 ordering (his own 庇护 newer than his barrier cuts behind it); 行险 drops his own held 庇护 for its 0.1 s
  re-judgement [ASSUMED: another source's returns with its next refresh]. 遥's bubbles stay separate (the client's
  damage_resistance[bonus] multiplies with the common damage_resistance[inf]).

Golden: no scenario moved — no unit of the corpus holds two 庇护 at once, and one source alone cuts exactly as before.

Tests: test/content/feedback5-protect.test.js (new, 2); kits_t6 (余), kits_alt_t6 (缪尔赛思), op_hodrer updated to the
shared key; kits_t1t2, op_helage, op_zuole pass. Docs: SIM.md §3, kits/README.md checklist 9.

server/sim/content/kits/ops/chess_char_6_03-yu.js

@@ -6,6 +6,7 @@ import {
   num, bv, tbb, moduleBb, live, opsOf, ANY, onDefaultSkill, selectedSkill, skillGridOf, AROUND8, onElementHit,
   elementDmg, aura,
 } from '../shared/tier6.js';
+import { holdProtect } from '../shared/tier1.js';
 
 /**
  * "传送至自身位置": a ground enemy that can reach `unit`'s tile on the ground grid is moved onto it (unblocked, its
@@ -89,9 +90,10 @@ function yu(bb, chess, def) {
     talents: [
       { install(battle, unit) { // 礼尚往来: 庇护 while blocking + DoT on blocked enemies
         const dr = num(t0.damage_resistance), sc = bv(t0, 'atk_scale'), er = bv(t0, 'ep_damage_ratio'), iv = Math.max(0.1, bv(t0, 'interval', 1));
-        // 庇护 (ba.protect): 受到的物理和法术伤害降低相应比例 — true / element damage is not reduced
+        // 庇护 (ba.protect): 受到的物理和法术伤害降低相应比例（同名效果取最高）— true / element damage is not reduced; the shared
+        // 庇护 (holdProtect: the strongest of every source holds)
         aura(battle, unit, 0.1, () => {
-          if (dr > 0 && unit.blocking.length) battle.addBuff(unit, { key: 'yu:shelter', mods: { physTakenMul: 1 - dr, artsTakenMul: 1 - dr }, duration: 0.2, refresh: 'replace' });
+          if (dr > 0 && unit.blocking.length) holdProtect(battle, unit, dr, 0.2, unit);
         });
         aura(battle, unit, iv, () => {
           for (const e of unit.blocking.slice()) {