feedback1f WT: 蒂比's 起飞 is 对地规避 — ground enemies no longer target or hit her while airborne

Official: ba.liftoff 起飞 "不阻挡地面敌人且不会被地面敌人攻击，可以阻挡飞行敌人"; PRTS 术语释义 起飞 "包含对地规避（无法被不同
阵营行动方式为地面的单位选中）… 起飞后单位的行动方式依旧是地面"; PRTS 异常效果 MOTION_TARGET_FREE; PRTS 行动方式 "起飞的干员仍然
是地面单位".

Cause: 起飞 was `unit.ground = false` (an operator on a high tile). Melee enemies were released, but every ranged
ground enemy kept shooting her and the AoE / skills of ground enemies hit her (控潮术师 6 hits in one S2 window).

Now 起飞 is the skill buff flag `liftoff`:
- targeting.js evadesGround: no ground enemy (not Unit.isFlying) selects her (canTargetAlly; the content picks that
  bypass it: 周围四格 additions, chain / bounce jumps, the 自行炮 shells); flyers, 近地悬浮 and 浮空 enemies still do.
- damage.js / Battle.applyStatus: a ground enemy's damage, element fill and statuses never land on her (area damage,
  shots under way); sourceless damage and `ignoreSelect` zones (【污染秽蚀】 "可对空，无视无法选择") still do.
- Battle._blockerFor: she blocks no ground enemy; flyers at the air radius as before.
- She stays a ground unit on her low tile: 污染秽蚀 at the low rate, 隐德来希 S2 can put a 血镰 on her (可对空).

server/sim/targeting.js

@@ -9,7 +9,7 @@
 // follow-up "阻挡了就一定要能打到"; Battle.blockedTargets), (2) profile priority (fly/lowDef/…),
 // (3) higher enemy taunt, (4) least remaining path distance to the goal, (5) earliest spawned. Air units
 // (Unit.isFlying: FLY, 近地悬浮, 浮空) need a profile that can hit them (`canHitFly`, never `groundOnly`). Enemy
-// priority: sortAllyTargets.
+// priority: sortAllyTargets. 起飞 (an ally's flag `liftoff`) = 对地规避: no ground enemy selects it (evadesGround).
 
 import { COLS, ROWS } from './constants.js';
 import { normDir, rotateOffset } from './dir.js';
@@ -68,16 +68,34 @@ export function canTargetEnemy(attacker, e, profile) {
  * "隐匿与'阻挡时解除'没有直接关系"). Devices are never targets (阻隔工事: obstacles nobody can select; “双眼皮”: 迷彩 and
  * off the enemy paths — PRTS). 迷彩 (flag `camou`, term ba.camou "不阻挡时不成为敌方普通攻击的目标") works the same way:
  * PRTS 异常效果 gives both anomalies the note "与'阻挡时解除'没有直接关系" [ASSUMED: enemy skills and splash selectors
- * treat 迷彩 like target selection — officially splash and selectors without a projectile ignore it].
+ * treat 迷彩 like target selection — officially splash and selectors without a projectile ignore it]. An airborne ally
+ * (起飞, flag `liftoff`) is never a target of a ground enemy (evadesGround).
  */
 export function canTargetAlly(e, a, ranged) {
   if (!a.alive || !a.deployed || a.hidden || a.kind === 'device') return false;
   const f = a.s.flags;
   if (f.untargetable || f.sleep) return false;
   if (ranged && (f.stealth || f.camou) && e.blockedBy !== a) return false;
+  if (f.liftoff && evadesGround(e, a)) return false;
   return true;
 }
 
+/**
+ * 对地规避 of an airborne ally (起飞, buff flag `liftoff` — 蒂比's skills): true when `src` is an enemy whose 行动方式 is
+ * ground, which then cannot select `a` (gamedata_const ba.liftoff "不阻挡地面敌人且不会被地面敌人攻击，可以阻挡飞行敌人";
+ * PRTS 术语释义 起飞 "包含对地规避（无法被不同阵营行动方式为地面的单位选中）"; PRTS 异常效果 MOTION_TARGET_FREE, a 无法选择
+ * effect that a selector whose 行动方式 is not ground ignores). Flyers, 近地悬浮 and 浮空 enemies (Unit.isFlying — PRTS
+ * 行动方式: a hovering unit "是真正的飞行单位", a levitated one is seen as a flyer) still select it; it stays a ground unit
+ * itself ("起飞的干员仍然是地面单位"), so they need no 对空 check. Used by every enemy selection (canTargetAlly), the damage
+ * pipeline and Battle.applyStatus (a ground enemy's area damage, statuses and hits under way skip it — PRTS 作战机制 "AOE
+ * 的判定是对攻击范围内的每个可以被选中的敌人进行判定"), and the content picks that bypass canTargetAlly (chain / bounce jumps,
+ * 周围四格 additions). Sourceless damage and abilities that "无视无法选择" (DamageInfo `ignoreSelect`: 【污染秽蚀】) are not
+ * selections and still reach it.
+ */
+export function evadesGround(src, a) {
+  return !!(a && a.s && a.s.flags.liftoff && src && src.side === 'enemy' && !src.isFlying);
+}
+
 const PRIORITY_FNS = {
   fly: (e) => (e.isFlying ? 0 : 1),
   lowDef: (e) => e.s.def,