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/shared/tier1.js

@@ -27,7 +27,7 @@
 // counter {id} · crit {id} · dp {n, id} · heal {id} · taunt {id} · summon {id, token} · pull {id} · sonic {radius} ·
 // shield {id} · overload {id} · takeoff {id} · sleep {id} · buff {id, kind} · reveal {id} · dodge (engine kind).
 
-import { COLS } from '../../../constants.js';
+import { COLS, TICK } from '../../../constants.js';
 import { absoluteRangeKeys, sortEnemyTargets } from '../../../targeting.js';
 import { offsetTile } from '../../../dir.js';
 import { bodyInKeys, bodyTileReach } from '../../../body.js';
@@ -94,6 +94,21 @@ export function onDamagedOn(battle, unit, fn, priority = 0) {
   return battle.on('damaged', (ctx) => { if (ctx.target === unit) fn(ctx); }, { owner: unit, priority });
 }
 
+/**
+ * 庇护 (gamedata_const 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）"; PRTS 术语释义 庇护): ONE effect per unit
+ * whoever grants it — battle.applyStrongest under this key, the strongest value holds and a weaker one resumes when it
+ * outlasts it. (遥's bubbles are a separate key, the client's damage_resistance[bonus] — they multiply with it.)
+ */
+export const PROTECT = 'protect';
+/** The mods of a 庇护 value: physical and arts damage taken ×(1 − v). */
+export const protectMods = (v) => ({ physTakenMul: 1 - v, artsTakenMul: 1 - v });
+/** A hold that outlives one tick and lapses in the next: refreshed every tick while its condition lasts. */
+export const PROTECT_TICK_HOLD = 1.5 * TICK;
+/** Hold 庇护 `value` on `target` for `duration` s (the shared PROTECT effect). */
+export function holdProtect(battle, target, value, duration, source = null) {
+  if (value > 0) battle.applyStrongest(target, PROTECT, { duration, value, mods: protectMods, source });
+}
+
 /** Targetable enemies inside `grid` (relative to the unit; null ⇒ current range), best targets first. */
 export function enemiesInGrid(battle, unit, grid, { n = 0, priority = null, canHitFly = true, groundOnly = false } = {}) {
   const keys = grid ? absoluteRangeKeys(grid, unit.tileR, unit.tileC, unit.dir, 0) : unit.rangeKeys;