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).

test/content/kits_alt_t2.test.js

@@ -362,7 +362,8 @@ test('2_13 蒂比 S1 专业喷绘技巧: DEFAULT trigger, takes off (skill range
     const range0 = u.baseRangeKeys.length;
     h.runUntil(() => u.skill.active, 3);
     assert.equal(started(h, u)[0].reason, 'DEFAULT');
-    assert.equal(u.ground, false, 'airborne');
+    assert.equal(u.s.flags.liftoff, true, 'airborne (起飞)');
+    assert.equal(u.ground, true, 'still a ground unit on her low tile');
     approx(u.s.atk, u.base.atk * (1 + bb.atk));
     assert.ok(u.rangeKeys.length > range0, 'skill range');
     const fl = h.spawn('f', { pos: [9, 5] });
@@ -374,7 +375,7 @@ test('2_13 蒂比 S1 专业喷绘技巧: DEFAULT trigger, takes off (skill range
     assert.equal(hits.length, atk.reduce((n, c) => n + c.targets.length, 0), 'one shot per target (no 3 连射)');
     h.runUntil(() => !u.skill.active, 40);
     h.step();
-    assert.equal(u.ground, true, 'landed');
+    assert.ok(!u.s.flags.liftoff, 'landed');
     done(h);
     // an enemy attack from outside her range never sets S1 off (S2's 受到攻击后触发 is not hers)
     const h2 = run({ defs: { enemies: { r: dummy('r', { atk: 300, bat: 1, range: 3.2 }) } }, units: [U(id, 9, 5, { carryState: READY })], enemies: [{ key: 'r', pos: [9, 8] }] });

test/content/kits_t1t2.test.js

@@ -962,7 +962,8 @@ test('2_13 蒂比: an incoming attack triggers 紧急赶场通知 and is dodged;
   assert.equal(h.hooksOf('skillStart').find((c) => c.unit === u).reason, 'TAKE_DAMAGE');
   assert.equal(u.stats.taken, 0, 'the triggering hit was dodged');
   approx(u.s.atk, u.base.atk * (1 + bb.atk));
-  assert.equal(u.ground, false);
+  assert.equal(u.s.flags.liftoff, true, 'airborne (起飞)');
+  assert.equal(u.ground, true, 'still a ground unit on her low tile');
   h.step();
   assert.equal(e.blockedBy, null, 'airborne: ground enemies are released');
   const fl = h.spawn('f', { pos: [9, 5] });