feedback1b WI: static-body enemies are never pushed or pulled (B5: 薄绿 vs drones)

Player report after 0.1.0: "飞机可以被薄绿的技能拉走". Real. PRTS 特殊机制 静态刚体:
such a unit "可以进入失衡状态…但物理层面上无法产生任何速度或移动", independent of
its movement type. Every air unit of the mode except “炎佑” lists it in its PRTS
天赋, and so does the ground boss 盐风主教昆图斯.

- build-data: STATIC_BODIES (from the enemies' PRTS pages, like HIT_AREAS)
  writes enemies.json `staticBody: true` on those 28 keys; data regenerated
- Battle._displaceable: a static body moves 0 tiles from every push or pull;
  the skills that reach it still hit it (薄绿 S2, 锏 S3, the hookmasters)
- 刺胄之弹 / 斩胄之剑 / 破胄之锤 also get 失衡免疫 (PRTS 天赋)
- ground enemies keep the 力度 − 重量 tables; the hovering 吉兆飞鳞 / 掠海漂移体
  stay 失衡免疫 while they hover and movable once grounded
- tests: the player's scenarios (薄绿 S2 vs 妖怪 / 寒霜, the act2 m01 drone), the
  data list, and an audit of every displacement source against ground, static
  air, dynamic air, hovering and 胄-shell targets

test/sim/playtest6-combat.test.js

@@ -410,7 +410,8 @@ test('#14 特效 pushes (PRTS 推与拉: one frame less of travel than 弹道 on
   approx(e.x, 4 + PUSH_TILES_EFFECT[1], 1e-6, '特效 column');
 });
 
-test('#14 锏 S3 归于宁静 slashes and pulls air units too (PRTS 备注 "※可对空。不会拖拽自身中心半径0.6708范围内的敌人")', REAL, () => {
+test('#14 锏 S3 归于宁静 slashes air units and pulls a non-static one (PRTS 备注 "※可对空。不会拖拽自身中心半径0.6708范围内的敌人")', REAL, () => {
+  // a synthetic dynamic flyer: the air units of the mode are all 静态刚体 — hit, never moved (test/sim/feedback1b-displacement.test.js)
   const id = 'chess_char_6_19_a';
   const h = makeBattle({
     defs: { enemies: { enemy_fly: foe('enemy_fly', { speed: 0, mass: 0, motion: 'FLY' }), enemy_near: foe('enemy_near', { speed: 0, mass: 0 }) } },