feedback7 R22-LATE: 引星棘刺 S1 度算浪波 — two alchemy units on one ally add their DEF (+60 +60), as their heals already did; golden: roster-033, roster-034 move

GitHub #388 (claim 1). Every S1 alchemy unit applied its DEF buff under one shared key ('thorn2:bastion'), so a second
unit over the same ally replaced the first one's buff (two units: DEF +60, not +120; a normal and an elite: +75, not
+135) while both units' heals landed. PRTS 引星棘刺 技能1 备注: 「效果均可叠加」. Each alchemy unit now has its own
DEF buff key (assigned at its first tick), so the buffs add (aggregateMods sums defFlat) and each lapses with its own
unit. S3's 不叠加 debuff is untouched.

Golden: roster-033 (a normal 引星棘刺 with S1, pass 1) and roster-034 (an elite one, pass 1) move — one operator's
consecutive S1 units overlap for a few seconds (6 / 7 s + 3 s 心相 against a 7 / 6 SP cost) and now add their DEF on
an ally both cover (033: killed 46 → 64, leaks 121 → 103; 034: damage taken by 5_13_b 41498 → 14903 …).
Tests: test/content/kits_alt_t5.test.js (+1: normal + elite on one ally = +135, the longer unit's +75 stays alone,
nothing afterwards; fails on the parent with +75).

server/sim/content/kits/ops/chess_char_5_15-thorn2.js

@@ -63,7 +63,10 @@ export default {
       if (z.type === 'guard') {
         const inZone = (a) => Math.abs(a.tileR - z.r) <= 1 && Math.abs(a.tileC - z.c) <= 1;
         const allies = battle.alliesFor(unit).filter(inZone);
-        for (const a of allies) battle.addBuff(a, { key: 'thorn2:bastion', duration: AURA_DUR, mods: mods({ defFlat: num(bb.def) }) });
+        // one DEF buff per alchemy unit, so two units on one ally add up (+60 +60; PRTS 度算浪波 备注 「效果均可叠加」,
+        // GitHub #388 — one shared key let the last unit's buff replace the other's)
+        z.defKey ??= `thorn2:bastion:${unit.id}:${unit.mem.bastionSeq = (unit.mem.bastionSeq ?? 0) + 1}`;
+        for (const a of allies) battle.addBuff(a, { key: z.defKey, duration: AURA_DUR, mods: mods({ defFlat: num(bb.def) }) });
         if (z.acc >= 1 - 1e-9) {
           z.acc -= 1;
           const heal = unit.s.atk * num(bb.hp_recovery_per_sec_ratio);