feedback1e WQ: healers that block keep healing (E2 not reproduced, locked by tests)

A community report said a medic blocking a roaming boss in a 炎 build stops
healing and strikes the boss, its 强力击-type skill included. The real sim
does not do that: every pure healer (医师 / 群愈师 / 疗养师 / 链愈师 / 行医,
the map characters, normal and elite, every skill) blocking an enemy keeps
healing and never targets it, under every bond as a member, with every
equipment item and on every boss / hidden field (卢西恩 and its phantom,
the 剑 / 锤). Official: PRTS 卫戍协议/帮助 "对于医疗干员（咒愈师分支除外），
攻击目标为需要治疗的单位". The only damage a pure healer deals is a bond's
own effect by its text (卡西米尔's pulse while blocking).

No behaviour change: the rule is spelled out in SIM.md and ai.js
acquireTargets, and test/sim/feedback1e-healers.test.js locks it (the
reported 炎 boss round, every healer x bond, items, heal-mode skills of
古米 / 塞雷娅 / 波登可, 咒愈师 and 吟游者, every boss template).

docs/SIM.md

@@ -189,7 +189,12 @@ front — `Battle.blockedTargets`, used by `ai.js acquireTargets` and the skills
 `sortEnemyTargets`; "自身这格内" rules name the blocked enemies separately — 瑕光 S2, PRTS 备注). A kit that picks its own
 targets from the range (`beforeAttack`) adds `battle.blockedTargets` to its candidates (深靛, 迷迭香 S3, 荒芜拉普兰德 S2,
 佩佩 S2, 灵知 S3, 远牙 S3); only skill texts that exclude targets keep their rule (普罗旺斯 S2: none above 80 % HP; 寒檀
-S2: icicles on random tiles of her range). This replaces the
+S2: icicles on random tiles of her range). The rule is for units whose attack hits enemies: a healer (dmgType `heal` —
+医师 / 群愈师 / 疗养师 / 链愈师 / 行医, the map characters 预备干员-医疗 / Touch — and a skill attack turned into a heal:
+古米 S1 / S2, 塞雷娅 S1, 波登可 S1) selects injured allies only and keeps healing while it blocks (PRTS 卫戍协议/帮助
+"对于医疗干员（咒愈师分支除外），攻击目标为需要治疗的单位"; PRTS 仇恨 HP_RATIO_NOT_FULL_ASC; `ai.js acquireTargets` returns
+before the blocked targets, the heal skills' DEFAULT trigger looks at injured allies — test/sim/feedback1e-healers.test.js);
+咒愈师 attack enemies and follow it. This replaces the
 playtest #5 QA's melee-only reading (PRTS 索敌的概念 "我方索敌优先级：阻挡（近战限定）"; "远程位干员…无法攻击到这个敌人");
 DESIGN §20 keeps the one-line flip (`Battle.blockedTargets` / `sortEnemyTargets` gated on a melee position again).