Playtest #5 fixes: hovering enemies, target order, blocking hand-over, 联防 knocked-out, elements, huge-boss hit area, maps, gear icon, phone HUD, 至简 price

- #1 近地悬浮 enemies count as air units (Unit.isFlying): ground-only attacks, splash, terrain and traps skip them;
  PRTS 不可对空 skill effects made ground-only; 掠海漂移体 / 吉兆飞鳞 drop modes; the bot plans them as air
- #2 an operator knocked out before 联防 is fielded and force-exited (PRTS 强制退场): it lies on its tile with the
  redeploy ring and redeploys (full timer [ASSUMED]); partners, observers and the server fallback included
- #3 element audit of every operator, item and enemy: 海嗣 numbers are official; bursts are 无来源, 元素脆弱 only
  raises 元素伤害, 元素抗性 applied, 盟约·辅助干员 fills all three gauges, 菲莱 / 哈洛德 / 纯烬 / enemy kits fixed
- #4 blocking by the official contact radius (0.7071): another operator in contact takes over at once when the
  blocker dies, withdraws or is stunned; melee blockers attack what they block
- #5 enemy target order per PRTS 索敌: blocker, special priority, taunt, last deployed; initial deploy 从上到下>从左到右,
  operators before summons; special priorities break ties by taunt then deploy order
- #6 act2 m01's normal-field blower machines (row 13) are drawn in the normal / 联防 views
- #7 Final Assault prep legality reads the player's half of the boss field (fence tiles deployable); all 11 stages
  audited against the official level files
- #8 regular settings gear; #9 the prep camera keeps the bench and temp rows clear of the shop bar on phones
- #10 huge bosses have the official 4.95 × 2.95 hit area (sim/body.js) and are 自缚 / unblockable
- #11 至简 costs 1: 购买价格为N's bb.price is a discount off the tier price, applied before other price effects
- DESIGN §19 and the normative §3 / §5 / §6 / §7 lines, SIM / META / DATA / PLAYING updated; 2595 unit tests and
  every browser suite green; dev recordings regenerated

server/sim/units.js

@@ -71,7 +71,8 @@ export class Unit {
     this.deployedAt = -Infinity;
     this.deathAt = -Infinity;
     this.respawnAt = Infinity;
-    this.deploySeq = 0;
+    this.deploySeq = 0;         // deployment counter; also the identity of one deployment (content: `seq === u.deploySeq`)
+    this.aggroSeq = 0;          // 仇恨 order (the later the more attacked): = deploySeq, except summons of the initial deployment
     this.spawnSeq = 0;
     this.elem = { burn: 0, neural: 0, necrosis: 0, apoptosis: 0, erosion: 0 };
     this.burstPending = null;   // { [element]: true } while that element's burst resolves (damage.js burstLocked)
@@ -142,7 +143,8 @@ export class Unit {
       physTakenMul: m('physTakenMul'),
       artsTakenMul: m('artsTakenMul'),
       trueTakenMul: m('trueTakenMul'),
-      elemTakenMul: m('elemTakenMul'),
+      elemTakenMul: m('elemTakenMul'),           // 元素损伤倍率: element gauge fills (damage.js applyElement)
+      elementalTakenMul: m('elementalTakenMul'), // 元素脆弱: 元素伤害 (the 'elemental' HP damage type)
       healingDealtMul: m('healingDealtMul'),
       healingTakenMul: m('healingTakenMul'),
       atkScaleMul: m('atkScaleMul'),
@@ -169,8 +171,17 @@ export class Unit {
 
   hasFlag(k) { return !!this.s.flags[k]; }
 
-  /** Ground unit: enemies that WALK and aren't levitated; ally units standing on a LOW tile. */
-  get isFlying() { return this.motion === 'FLY'; }
+  /**
+   * Air unit (空中单位) for every targeting / ground-only rule: FLY movers, and enemies that hover (近地悬浮, buff flag
+   * `float` — PRTS 术语释义 ba.float "算作空中单位"; they keep walking the ground path) or are levitated (浮空, gamedata_const
+   * ba.levitate "变为空中单位"). Movement and pathing read `motion`, never this.
+   */
+  get isFlying() {
+    if (this.motion === 'FLY') return true;
+    if (this.side !== 'enemy') return false;
+    const f = this.s.flags;
+    return !!(f.float || f.levitate);
+  }
 
   get hpRatio() { const mh = this.s.maxHp; return mh > 0 ? this.hp / mh : 0; }