Playtest #3 fixes: lost models, picking, live LP, temp overflow, 蕾缪安 S3, 回环射手, FX, detail card, spinners

- #1 lost operator models: the Spine store no longer hands out a skeleton whose unload is in flight
  (PIXI.Assets.unload is async); eviction runs 1 s after a release and the empty-scene budget only after 3 s
- #7 picking: one shared rule (render/pick.js, pixel probe where bodies overlap) for prep/battle clicks,
  hover, the enemy pen and equipment drops; the drag ghost stands on its drop tile; hover probes capped
  at one per frame
- #2 the top-bar LP drops live as the own battle's enemies enter the blue gate (−N, 联防中), teammates'
  pending LP in the team panel
- #3 temp overflow pieces that arrive after a prep deadline survive through the next prep (tempDue);
  temp-row warning and ready-button reason
- #4 蕾缪安 S3: locks every 0.5 s, then one shell every 0.3 s in lock order (PRTS notes), bombardShell fx
- #5 回环射手: real boomerang (out 15, back 3.75 tiles/s, attack only when every boomerang is caught)
- #6 visible projectiles, muzzle flashes, slashes, skill bursts and auras at unchanged frame cost
- #8 特质 right under the detail card header, with its official type icon
- #9 no spinning busy cursors / spinners next to texts; game data warmed before the match
- docs, recordings and tests updated (2414 unit tests, all browser suites green)

public/js/ui/components.js

@@ -111,7 +111,9 @@ export function Chevrons({ count = 3, dir = 'right', tone = 'mint', animated = t
 // ---- Button ------------------------------------------------------------------------------------
 
 /**
- * Button.
+ * Button. `loading` (a request in flight): disabled and dimmed, and after a short delay a thin bar sweeps along its
+ * bottom edge (css .btn__busy) — never a spinning ring or a wait cursor, which read as "this text is still loading from
+ * the server" (user playtest #3 item 9); the icon stays.
  * @param {{ variant?: 'primary'|'secondary'|'danger'|'amber'|'ice'|'ghost', size?: 'sm'|'md'|'lg'|'xl',
  *   icon?: string, iconRight?: string, loading?: boolean, disabled?: boolean, block?: boolean, square?: boolean,
  *   active?: boolean, onClick?: Function, type?: string, title?: string, class?: string, children?: any }} props
@@ -126,9 +128,10 @@ export function Button({
       active && 'is-active', loading && 'is-loading', cls)}
     disabled=${isDisabled} aria-busy=${loading ? 'true' : undefined} aria-pressed=${active ? 'true' : undefined}
     onClick=${(e) => { if (!isDisabled && onClick) onClick(e); }} ...${rest}>
-    ${loading ? html`<span class="btn__spin" aria-hidden="true"></span>` : icon ? html`<${Icon} name=${icon} class="btn__icon" />` : null}
+    ${icon ? html`<${Icon} name=${icon} class="btn__icon" />` : null}
     ${children != null && children !== false ? html`<span class="btn__label">${children}</span>` : null}
     ${iconRight ? html`<${Icon} name=${iconRight} class="btn__icon btn__icon--right" />` : null}
+    ${loading ? html`<span class="btn__busy" aria-hidden="true"></span>` : null}
   </button>`;
 }