Playtest #4 fixes: tile picking, knocked-down state, element gauges, draft timer, live stats, shop items, drones, 赫默, 炎佑, UI flash

- #1 picking by the tile under the pointer (prep, battle, pen, equipment drops); the dragged model stays
  under the pointer (mouse and touch); pixel probe removed; phone ghost-click on the underframe fixed
- #2 two-tap confirm on 机变 cards (like the shop)
- #3 a 同盟 room with one human is untimed like 独立模拟 (no countdown outside battles)
- #4 strategy draft: one synced countdown, 30 s per human turn, timeout takes the highlighted band
- #5 special 维式重锤 (4) and 突变细胞 no longer sold; item card shows where they come from
- #6 operator skill-mode sounds no longer play on normal attacks (纯烬艾雅法拉 and 55 others)
- #7 detail card shows live battle stats and the prep-time battle-start stats (g.unitStats)
- #8 official element gauges on units; burst cooldown (阻回) per PRTS
- #9 knocked-down operators stay on their tile with a redeploy countdown ring
- #10 drone behaviour per PRTS (暴鸰, 先兆者 shells, 黑云, 萨科塔之眼)
- #11 赫默's drone only from her skill; placeable summons limited to talent tokens
- #12 炎佑 stays where it is with no enemies; 祛恶之焰 as a continuous channel
- #13 the occasional giant bond icon (loading texture scaled ×46) fixed
- docs (DESIGN §18), recordings, data and tests updated (2467 unit tests, all browser suites green)

server/sim/skills.js

@@ -1,7 +1,8 @@
 // server/sim/skills.js — skill runtime: SP, charges, trigger rules, kinds, SkillSpec interpretation (DESIGN §5.6).
 //
 // SP types: 'time' (+spRecovery/s), 'attack' (+1 per attack), 'hurt' (+1 per hit taken), 'none'.
-// No SP gain while a duration/ammo/toggle skill is active, while stunned, or while the unit has the noSp flag.
+// No SP gain while a duration/ammo/toggle skill is active, while stunned, or while the unit has the noSp flag (阻回: no SP
+// gain of any kind — time, attack, hurt or granted).
 // Charges (maxCharges > 1): SP fills to spCost → +1 charge (SP restarts) until charges == max (SP stays full).
 // Trigger rules: DEFAULT (ready + about to attack/heal + enemy / injured ally in the INITIAL range — or, checked every
 //   tick, an enemy inside one of the content trigger ranges added with addTriggerRange: 海嗣, 流形),
@@ -176,6 +177,8 @@ export class SkillRuntime {
   gainSp(amount, reason = 'time', silent = false) {
     if (this.noSkill || this.kind === 'passive' || !(amount > 0)) return 0;
     if (this.active && this.isTimed && reason !== 'init') return 0;
+    // 阻回 (the operators' 凋亡 burst, damage.js): "停止并阻止任意形式的技力回复" — no SP of any kind (time, attack, hurt, gifts)
+    if (reason !== 'init' && this.unit.s.flags.noSp) return 0;
     let cost = this.spCost;
     if (this.charges >= this.maxCharges && this.sp >= cost) return 0;
     let amt = amount;