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)

docs/ASSETS.md

@@ -212,6 +212,8 @@ Other renderer rules from research 07 §5.4–5.5:
   - Without a Spine, draw the avatar sprite with a bob tween.
   - `spineVariant` names the skin-variant model that stands in for the missing default model.
 - **Enemies without a spine** (for example `enemy_9016_acstmr`): draw `icon` in a diamond. Enemies with no manifest entry at all (`enemy_5601_entlec` 心烛): draw a procedural glyph.
+- **Battle effects** (projectiles per kind, hit sparks and slashes, skill bursts and auras, 蕾缪安's lock reticles and shells, 回环射手 boomerangs — DESIGN §17.3) are procedural: the FX atlas is drawn at run time (`public/js/render/textures.js`), so they need no downloaded or local art. The local client does have battle effect art — `battle/[pack]common.ab` holds per-weapon projectile sprites (`projectile_arrow(_new)`, `projectile_crossbow(_new)`, `projectile_yuki`, `img_fx_light_01/02`, `trail_11`), and the per-character `battle/prefabs/effects/*.ab` are particle systems whose textures live in other bundles — but none of it is extracted: the sim's `arrow` also covers gun snipers, and friends joining a game may not have the local art.
+- **Spine memory** (`public/js/assets.js`): skeletons are refcounted in an LRU with an idle budget (`SPINE_IDLE_BYTES`, 48 MB) and a 15 s grace; eviction runs `SPINE_EVICT_DELAY_MS` (1 s) after a release, the "no scene on screen" budget (0 bytes) applies after `SPINE_QUIET_DELAY_MS` (3 s) with nothing referenced, and a skeleton whose unload is still in flight is never handed out again — a new load waits for the unload (DESIGN §17.1; it used to leave operators invisible after a battle → prep switch).
 
 ### Looking up `data/chess.json` asset ids