0.2.4-dev: round-29 community fixes and the official shared card pool

- Shared card pool and item stock as in the official mode (the owner's request, from the 路标档案馆 video and public notes): solo low-tier exceptions, co-op operators x2, shared item stock with special-item exceptions, normal / advanced occupancy 1 / 2, re-check on buy, 机变 exhaustion, release on consume / destroy / elimination; 整备 never exceeds stock; invariant held <= cap.
- 突袭: one taunt-first reselect right after a revive (the owner's rule); ordinary polls and redeploys keep the 0.2.3 rule; a revive on an enemy's tile stays. #475: online boss / hidden-boss Raid may land on the empty half (owner-limited scope).
- 浊心斯卡蒂 S1 x 坚守 no longer bounce redirected damage, and the two shares conserve the hit (idea of PR #464 by @HappyTanuki).
- Operator fixes adapted from PRs by @Xinglan233 (#459 哈洛德 S2 elemental trigger, #460 涤火杰西卡 shield on the four adjacent tiles, #461 家族徽章 first hit after stealth, #462 松果 S2 regrow per deploy); 克莱门莎 S2 splash 1.1 / 100% ATK and air auto-trigger (#467); 白面 copying 歌蕾蒂娅 / 余 skips the three-member condition (#473, the owner's video).
- 香槟炸弹 is not chosen by friendly auras / heals (PR #468 / #476 by @Siornya); 琳琅诗怀雅 coin balance (PR #450 by @IceCodeNew); Touch prep display (PR #451 by @YinqiMargatroid); lobby header (PR #471 by @YuriRestia); Japanese UI terms (PR #448 by @scutkane).
- AI-only boss countdown grace, render-failure cache / recovery without restarting a battle, device units kept on a same-field re-entry, DIY detail / skill previews, large-text result buttons.
- golden: battle families equal 0.2.3 except diy-135 / diy-136 (克莱门莎); all 18 release matches move through the shared pool, every flip named in docs/history/0.2.4.md §29.12; two coverage scenarios added.

public/js/render/app.js

@@ -432,6 +432,13 @@ export async function createFieldView(host, options = {}) {
   }
   // Attach the board only after synchronous setup completes; enable3d also guards late arrivals.
   const boardReady = Promise.all([threePromise, packPromise]).then(([THREE, pack]) => (THREE && pack ? enable3d(THREE, pack) : false), () => false);
+  let boardRetry = null;
+  function retryBoard() {
+    if (!want3d || destroyed || board3d || recover.off || recover.timer || boardRetry) return;
+    boardRetry = Promise.all([loadThree(), loadBoardPack(assets)])
+      .then(([THREE, pack]) => enable3d(THREE, pack), () => false)
+      .finally(() => { boardRetry = null; });
+  }
   // the official soft shadow sprite replaces the procedural one once loaded (may already be cached; asked again when the
   // manifest arrives late)
   let shadowAsked = false;
@@ -797,8 +804,16 @@ export async function createFieldView(host, options = {}) {
       if (e.area === 'board' && info.dir && !held.has(e.uid) && typeof v.setDir === 'function') v.setDir(info.dir);
     }
     for (const k of [...views.keys()]) if (String(k).startsWith('p:') && !seen.has(Number(String(k).slice(2)))) dropView(k);
-    // the boss round's prep: the pair partner's board on its half of the boss field (item 51; display only)
-    syncMates(prepXf.kind === 'bossPrep' && src.bossMate && Array.isArray(src.bossMate.units) ? src.bossMate.units : []);
+    // The 外勤医疗 reserve medic is visible before battle but not a movable board piece. Map its board-space slot to
+    // the displayed boss half exactly as for the player's own pieces; the partner's units already use field coordinates.
+    const mapChars = Array.isArray(src.prepMapChars) ? src.prepMapChars.map((u) => {
+      if (!u || !Number.isInteger(u.x) || !Number.isInteger(u.y)) return null;
+      const p = prepXf.toDisp(u.y, u.x);
+      const dir = prepXf.dirToDisp(u.dir);
+      return { ...u, x: p.col, y: p.row, dir, facing: dir === 'LEFT' ? -1 : 1 };
+    }).filter(Boolean) : [];
+    const mate = prepXf.kind === 'bossPrep' && src.bossMate && Array.isArray(src.bossMate.units) ? src.bossMate.units : [];
+    syncReadOnlyPrepUnits([...mapChars, ...mate]);
     prepPieces = list.filter((e) => e.key && views.has(e.key));
     if (dragState && !views.has(dragState.key)) { drag.reset(); endDragVisual(false); }
     holdScene(false); // the prep pieces reference their models now (a battle's hold ends here)
@@ -806,11 +821,10 @@ export async function createFieldView(host, options = {}) {
   }
 
   /**
-   * The pair partner's pieces in the Final Assault / Hidden Core prep (m.private bossMate units: UnitInfo in boss-field
-   * coordinates, facing as the battle will place them): read-only 'm:<uid>' views — not prep pieces, so they are never
-   * picked, dragged or swept with the own ones; a view is rebuilt when its body, tile or facing changes.
+   * The reserve medic and a boss pair's partner pieces: read-only 'm:<uid>' views. These are not prep pieces, so they
+   * are never picked, dragged or swept with the own board; a view is rebuilt when its body, tile or facing changes.
    */
-  function syncMates(units) {
+  function syncReadOnlyPrepUnits(units) {
     const keep = new Set();
     for (const u of units) {
       const info = u && Number.isInteger(u.uid) ? renderInfo({ ...u, id: `m:${u.uid}` }) : null;
@@ -1747,6 +1761,7 @@ export async function createFieldView(host, options = {}) {
   // load it again at once (their bounded retries never run while hidden: no frames).
   function onAssets() {
     if (destroyed) return;
+    retryBoard();
     loadShadow();
     loadMountains();
     if (mode === 'prep' && lastPrep) setPrep(lastPrep.ps, lastPrep.o);
@@ -1758,6 +1773,7 @@ export async function createFieldView(host, options = {}) {
   setupCleanup.push(() => offAssets?.());
   const onVisible = () => {
     if (destroyed || globalThis.document?.visibilityState !== 'visible') return;
+    retryBoard();
     if (assets.loaded === false && typeof assets.ready === 'function') assets.ready();
     for (const v of views.values()) v.retryAssets?.();
     for (const v of penViews.values()) v.retryAssets?.();