feedback1f WV: a knocked-out operator keeps its tile; 突袭 never lands on it

Player report F5 after 0.1.0: "突袭盟约的干员会移动到濒死干员的尸体上".

Real. A knocked-out operator left the occupancy map at once and only its
home tile stayed reserved. A 突袭 member that fell after its jump lay on the
landing tile, which nothing reserved, so the next member's jump (same target,
same scoring) landed on it; and a member's timed redeploy came back on its home
where a teammate that had jumped there lay. Real matches (six real 突袭
members, 战场#07 / #08, R6 / R9 / R12, 96 battles): 6 placements on a body
(3 jumps, 3 home redeploys) before, 0 of 526 jumps after.

Official (PRTS 卫戍协议/帮助, 作战阶段 / 单位部署):
- "干员退场后…原地留下一个“倒地干员”…满足再部署条件时，移除场上的该倒地干员
  并自动部署至该位置"
- "倒地干员所在地块视为可部署，但所有我方单位在此处的部署行为将被阻止"
- "若干员被击倒的位置为其他干员或召唤物的初始位置，则在被击倒后，尝试返回其
  自身的初始位置"

Now (sim/Battle.js):
- A knocked-out operator lies on `unit.body`: the tile it fell on, or its
  own home when it fell on another board piece's home and its home is free
  (one attempt at the knock-out, assumed). x / y / tileR / tileC keep where
  it fell, so the kill / death handlers still act there.
- Every redeploy comes back there (restTile): the timed one, 不屈's and
  阿戈尔's. A retreated operator still comes back on its home.
- downOn(r, c): _deploy (redeploys, the 突袭 landing, summons), spawnDevice
  and relocate refuse the tile for every ally of the field; isReservedTile
  reports it, so every automatic picker skips it (突袭 raidTile, tactical
  points, summon / device pickers, 维娜's lions). The kit helpers that kept
  their own home-tile loop (tier1 summonTileFree, tier3 / tier4 freeTile) go
  through isReservedTile.
- b.snap `down` entries gain the body tile: [id, respawnAt, respawnTime,
  state, row, col]. DOWN_STATE.WAIT_TILE becomes a safeguard only.

Tests: test/sim/feedback1f-downed-tile.test.js (real Match / PlayerState /
BattleSpec runs with real 突袭 chess, the 突袭 jump, the engine refusals,
the return home); downelem and bonds_addon follow the official rule.

server/sim/content/bonds/addon/battle.js

@@ -25,13 +25,16 @@
 //   突袭 raidShip      member idle ≥ no_attack_duration s (or skill ready) with no enemy in range → "保留技力立即再部署"
 //                      next to the most advanced ground enemy, on a free tile its position may be deployed on
 //                      (grid.canStand: never the 深水区 — player report #3 after 0.1.0, members dropped into 战场#08's
-//                      pool after an enemy wading in it): a real redeployment (retreat + free redeploy on the
-//                      landing tile, full HP, `deploy` fires — 部署时 traits such as 史尔特尔, 突袭手雷, 卡西米尔, 叙拉古)
-//                      with its SP / charges kept (engine redeploy tile + keepSp); ATK/HP +(base + per·L)
-//                      until it leaves the field; later redeploys use its board tile again;
+//                      pool after an enemy wading in it; Battle.isReservedTile: never a tile a knocked-out operator
+//                      lies on — player report F5, members landed on a fallen teammate): a real redeployment (retreat +
+//                      free redeploy on the landing tile, full HP, `deploy` fires — 部署时 traits such as 史尔特尔,
+//                      突袭手雷, 卡西米尔, 叙拉古) with its SP / charges kept (engine redeploy tile + keepSp); ATK/HP
+//                      +(base + per·L) until it leaves the field; knocked out after a jump it lies where it fell and
+//                      comes back there (the engine's rest tile, Battle._layBody — PRTS 卫戍协议/帮助 "原地留下一个
+//                      “倒地干员”…自动部署至该位置"; its own home when it fell on another board piece's home);
 //                      L ≥ power_bond_stack_cnt: every operator ASPD +power_attack_speed
-//   不屈 indomShip     ground operator knocked out → p = min(1, base + per·L) immediate free redeploy; tier 2: every
-//                      operator on the field +sp SP
+//   不屈 indomShip     ground operator knocked out → p = min(1, base + per·L) immediate free redeploy where it lies
+//                      (the engine's rest tile); tier 2: every operator on the field +sp SP
 //   协防 emptyShip     all operators phys/arts taken ×(1 − damage_resistance); members dealt ×damage_scale_normal
 //                      (elite ×damage_scale_extra)
 //   独行 soloShip      the member(s) ATK +atk, HP +max_hp, +sp SP on every deploy
@@ -289,8 +292,9 @@ function raidPoll(battle, st) {
 
 /**
  * "保留技力立即再部署": retreat the unit and redeploy it for free on (r, c) with its SP / charges kept (engine redeploy
- * `tile` + `keepSp`: restored before the `deploy` handlers run; the board tile stays the home of later redeploys).
- * Should the landing fail, the unit goes straight back to its home tile (never stranded off the field).
+ * `tile` + `keepSp`: restored before the `deploy` handlers run; the board tile stays its home). Should the landing fail
+ * (raidTile skips taken, reserved and body tiles, so only content refusing it), the unit goes straight back to its home
+ * tile (never stranded off the field).
  * Returns 'raid' | 'home' | false.
  */
 function raidRedeploy(battle, u, r, c) {

server/sim/content/bonds/core.js

@@ -400,9 +400,10 @@ function installEgir(battle, pid, bb, members) {
   battle.on('battleStart', () => devour(battle, pid, bb, members), { once: true });
   if (!reached(battle, pid, 'egirShip', bb.power_bond_char_cnt)) return;
   // 5: "前3名【阿戈尔】干员首次被击倒时立刻复活" — PRTS: the knocked-out unit's next deployment has 0 redeploy time and
-  // 0 cost, i.e. it IS knocked out (被击倒 triggers, 克莱门莎, 幽灵鲨 … fire) and redeploys at once on the tile it was
-  // knocked out on (engine redeploy `tile`: a raid-relocated member comes back where it fell, later redeploys use its
-  // board tile) with full HP, SP reset and `deploy` effects (卡西米尔 / 叙拉古). Death priority 11: before 不屈 (10),
+  // 0 cost, i.e. it IS knocked out (被击倒 triggers, 克莱门莎, 幽灵鲨 … fire) and redeploys at once where it lies (the
+  // engine's rest tile, Battle._layBody: the tile it was knocked out on — a raid-relocated member comes back where it
+  // fell —, or its own home when it fell on another board piece's home; PRTS 卫戍协议/帮助 §作战阶段 单位部署) with full
+  // HP, SP reset and `deploy` effects (卡西米尔 / 叙拉古). Death priority 11: before 不屈 (10),
   // whose redeploy "also consumes a 复活 charge" — with this order the charge is always the one used, same outcome.
   const memberSet = new Set(members);
   const max = Math.max(0, Math.floor(num(bb.max_free_respawn_cnt, 0)));
@@ -412,7 +413,7 @@ function installEgir(battle, pid, bb, members) {
     if (c.reason !== 'killed' || !memberSet.has(u) || st.knocked.has(u)) return;
     st.knocked.add(u);
     if (st.revives >= max || u.alive || u.removed) return;
-    if (!battle.redeploy(u, { free: true, tile: [u.tileR, u.tileC] }) && !battle.redeploy(u, { free: true })) return;
+    if (!battle.redeploy(u, { free: true })) return;
     st.revives++;
     S.fxOn(battle, 'revive', u, 'bond:egirShip', 'respawn', { n: st.revives });
   }, { priority: 11 });

server/sim/content/kits/tier1.js

@@ -181,16 +181,12 @@ export function makeZone(battle, caster, { x, y, radius, duration, interval = 1,
 }
 
 /**
- * A tile a summon may take: inside the field, nobody on it, and not the home tile of a board unit that has not
- * deployed yet / waits to redeploy (a summon there would stop that operator from redeploying until it leaves).
+ * A tile a summon may take: inside the field and not reserved (Battle.isReservedTile: nobody on it, no knocked-out
+ * operator lying there, not the home tile of a board unit that has not deployed yet / waits to redeploy — a summon
+ * there would stop that operator from redeploying until it leaves).
  */
 export function summonTileFree(battle, r, c) {
-  if (!Number.isInteger(r) || !Number.isInteger(c) || !battle.grid.inRect(r, c) || battle.unitAt(r, c)) return false;
-  for (const u of battle.allyUnits) {
-    if (u.alive || u.removed || u.kind === 'device') continue;
-    if (u.homeR === r && u.homeC === c) return false;
-  }
-  return true;
+  return Number.isInteger(r) && Number.isInteger(c) && battle.grid.inRect(r, c) && !battle.isReservedTile(r, c);
 }
 
 /** First free tile around `unit` (Chebyshev ring 1, front first — offsets rotated by its direction) where `ok(r, c)` holds. */

server/sim/content/kits/tier3.js

@@ -125,14 +125,12 @@ function textNum(text, re, fallback) {
   return /^\d+(\.\d+)?$/.test(m[1]) ? +m[1] : (CN_NUM[m[1]] ?? fallback);
 }
 /**
- * A tile a summon may take: inside the field, nobody on it, and not the home tile of an ally that has not deployed
- * yet / waits to redeploy (the initial deployment runs top→bottom: a summon placed while it runs must not steal a
- * later board unit's tile — that unit would never deploy; a dead operator must be able to come back).
+ * A tile a summon may take: inside the field and not reserved (Battle.isReservedTile: nobody on it, no knocked-out
+ * operator lying there, not the home tile of an ally that has not deployed yet / waits to redeploy — the initial
+ * deployment runs top→bottom: a summon placed while it runs must not steal a later board unit's tile).
  */
 function freeTile(battle, r, c) {
-  if (!Number.isInteger(r) || !Number.isInteger(c) || !battle.grid.inRect(r, c) || battle.unitAt(r, c)) return false;
-  for (const u of battle.allyUnits) if (!u.alive && !u.removed && u.kind !== 'device' && u.homeR === r && u.homeC === c) return false;
-  return true;
+  return Number.isInteger(r) && Number.isInteger(c) && battle.grid.inRect(r, c) && !battle.isReservedTile(r, c);
 }
 /** Walkable ground tile a melee summon can stand on. */
 const groundTile = (battle, r, c) => battle.grid.groundPassable(r, c) && battle.grid.canStand(r, c);

server/sim/content/kits/tier4.js

@@ -119,10 +119,13 @@ const reveal = (battle, enemies) => { for (const e of enemies) if (e.s.flags.ste
 function shove(battle, e, from, force) {
   return e && e.alive ? battle.push(e, num(force, 0), { from }) : 0;
 }
-/** Free tile for a summon/device: in the rect, standable, empty and not the home tile of any ally (dead ones redeploy there). */
+/**
+ * Free tile for a summon/device: in the rect, standable, not reserved (Battle.isReservedTile: empty, no knocked-out
+ * operator lying there) and not the home tile of any ally (dead ones redeploy there).
+ */
 function freeTile(battle, r, c, { ranged = false, ground = false } = {}) {
   if (!Number.isInteger(r) || !Number.isInteger(c) || !battle.grid.inRect(r, c)) return false;
-  if (battle.unitAt(r, c)) return false;
+  if (battle.isReservedTile(r, c)) return false;
   if (!battle.grid.canStand(r, c, { ranged })) return false;
   if (ground && !battle.grid.groundPassable(r, c)) return false;
   for (const u of battle.allyUnits) if (!u.removed && u.homeR === r && u.homeC === c && u.kind !== 'device') return false;