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.

docs/design/engine.md

@@ -224,3 +224,12 @@ the hook-depth guard on scaled hit-count HP; the guard remains unchanged for oth
   as well as by its aura tick, including the first hit and immediately after the last companion leaves.
 
 Sources and the feedback items requiring no simulation change are recorded in [§28.25](../history/0.2.3.md#2825-community-feedback-of-2026-10-10).
+
+Community corrections in §29 are normative: Raid's one reselect after a revive uses taunt then route distance and jumps while unblocked, after refreshing contact on the current tile; ordinary polls stay on route distance and the empty-range rule. Healing cast conditions include curable elemental injury; Pinecone S2 growth restarts per deployment; crest consumption is checked on damage. Mixed Skadi/Stead redirects preserve ancestry and both take their share from the pre-redirect hit, so the victim keeps the remainder and the total is conserved. Clementia S2 secondary splash is 100% ATK within a 1.1 collision radius (four additional ground targets), while its main hit and 1.5-radius vortex keep their own coefficients. Final-mode leaders retain their erosion immunity, explicitly stated in the PRTS mode tips. 整备 does not upgrade a purchase when the golden's second copy would exceed shared item stock, and it does not spend its charge in that case.
+
+Raid alone may land on an empty deployment half in multiplayer (`mode_multi_*`) Final Assault / Hidden Core battles
+(#475, maintainer-approved, §29.13): rows 2–5, cols 2–18, subject to the existing field rect, terrain, occupied/downed
+tile and attack-reach checks. Hand/temp rows, empty halves in single-player mode or lone-helper 联防 stay excluded.
+The general `onOwnBoard`/`onFieldBoard` contracts, other movement, summons and preparation placement remain unchanged.
+
+香槟炸弹 also rejects ordinary allied auras and inspiration as a device, through its shared internal selection barrier (§29.11). This does not isolate other unhealable summons or alter its detonation.