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)

public/js/ui/components.js

@@ -342,6 +342,9 @@ export function secondsLeft(deadline) {
 
 /**
  * 7-segment countdown with "COUNTDOWN" micro label and a 5-bar gauge; turns orange ≤ warnAt s.
+ * Untimed (no `seconds` and no deadline — the server sends deadline 0 for every phase outside the battles of a solo
+ * match, Match.soloUntimed): renders nothing at all. It used to draw a "--" placeholder with the COUNTDOWN label,
+ * which reads as a timer (user playtest #4 item 3; css/screens/loadout.css keeps hiding the old placeholder).
  * @param {{ deadline?: number, seconds?: number, total?: number, warnAt?: number, label?: string,
  *   size?: 'sm'|'md'|'lg', gauge?: boolean, onExpire?: Function, class?: string }} props
  *   deadline: server epoch ms (live); seconds: static value (overrides deadline); total: seconds for the gauge.
@@ -364,6 +367,8 @@ export function Countdown({ deadline, seconds, total, warnAt = 10, label = 'COUN
     }
   });
 
+  // untimed phase: no timer on screen (hooks above run unconditionally, so the component may toggle freely)
+  if (remain == null) return null;
   return html`<div class=${cx('countdown', `countdown--${size}`, warn && 'is-warn', cls)} role="timer" aria-label=${remain == null ? '无倒计时' : `剩余${remain}秒`}>
     <div class="countdown__main">
       <${SevenSeg} text=${text} tone=${warn ? 'orange' : 'mint'} flicker=${warn && remain > 0} />