feedback7 R22-GHSIM: 假想敌：骨刺 changes model with its 隐匿 at once — the three-headed snake (*_A) while hidden, its *_B set when blocked or revealed, back to *_A when hidden again (GitHub #296, PR #365 by @Sukvii, render part); golden: unchanged

The contributor's code (render/spine.js syncFormPose, the render/units.js wiring and FORMS entry, the headless
test/render/forms.test.js block), applied from PR #365, so they are the author of this commit. Maintainer side: the
hard-coded Spine id became a STEALTH_FORMS table (form while the stealth bit is off), comments and docs/ASSETS.md
reworded. Not ported: the PR's sim targeting rewrite (content/enemies/invisible.js), its enemies_bosses tests, its
roster.json and the Chrome suite (forms.browser.test.js, not run here).

Seen (#296, FrogThai): a blocked 骨刺 kept the snake. The sim already sends UF.STEALTH only while its 隐匿 is effective
(not blocked, not revealed — targeting.js enemyStealthed); the view now keys the FORMS 'revealed' clip set (Idle_B /
Move_B / Die_B / Attack_B, all in the skeleton) off that bit in UnitView.sync — before a DIE of the same snapshot — and
re-poses at once: a running attack continues in the other attack clip at the same point relative to its strike frame
(Attack_A hit 0.533 s, Attack_B 0.733 s; a pending wind-up still strikes on time), a stun / idle restarts on the new set
without a crossfade, and a frozen skeleton is posed with update(0); a model loaded later is posed the same way.
Golden: unchanged (render only).

public/js/render/units.js

@@ -190,6 +190,9 @@ export const EL_BAR = Object.freeze({ icon: 0.15, min: 8, max: 15, enemy: 0.8, g
  * → UnitView.setForm), per Spine id; the mode's roles override the manifest's (data/assets.json anims), `change` plays
  * once first:
  * - 掠海漂移体 (PRTS: 受晕眩/沉睡/冻结影响后进入爬行模式 — for good) crawls on its *_02 clips after 'Change';
+ * - 假想敌：骨刺 (GitHub #296, PR #365): not an fx — its form follows the snapshot's stealth bit (STEALTH_FORMS): the
+ *   manifest's *_A (the three-headed snake) while its 隐匿 is on, 'revealed' *_B the moment it is blocked or revealed, *_A
+ *   again when the 隐匿 is back; no change clip, a running attack / stun pose carried over (SpineActor.syncFormPose);
  * - 暴鸰 flies on its bomb-less *_2 clips once its one bomb left (the official prefab's mode S1: Move→Move_2, Idle→Idle_2,
  *   Die→Die_2; user feedback after 0.1.0, D4: the bomb used to stay under the drone — no change clip, the drop is its
  *   Attack clip);
@@ -224,6 +227,12 @@ export const EL_BAR = Object.freeze({ icon: 0.15, min: 8, max: 15, enemy: 0.8, g
  *   built for the knock-out — and one rebuilt while it is down — the 替身's death clip; it stands up as the 本体.
  * A kind without a clip set of this skeleton (barriers, charges, …) changes nothing. 吉兆飞鳞's 晕眩模式 is its Stun clip.
  */
+/**
+ * Enemy forms that follow the snapshot's stealth bit (UF.STEALTH: the sim sends it only while the enemy's 隐匿 is on —
+ * not blocked, not revealed) instead of a sim fx, per Spine id: the FORMS kind drawn while the bit is OFF; the manifest's
+ * clips while it is on. Switched at once (UnitView.sync, and for a model loaded later the load callback).
+ */
+export const STEALTH_FORMS = Object.freeze({ enemy_9008_acbunn: 'revealed' });
 const loop = (name, via = null) => Object.freeze(via ? { begin: null, loop: name, end: null, via } : { begin: null, loop: name, end: null });
 const clipSet = (idle, move, die, attack = null) => Object.freeze({
   idle, deploy: idle, die, move: loop(move),
@@ -274,6 +283,9 @@ export const FORMS = Object.freeze({
   enemy_2025_syufo: Object.freeze({
     crawl: Object.freeze({ change: 'Change', roles: clipSet('Idle_02', 'Move_02', 'Die_02', 'Attack_02') }),
   }),
+  enemy_9008_acbunn: Object.freeze({
+    revealed: Object.freeze({ change: null, roles: clipSet('Idle_B', 'Move_B', 'Die_B', 'Attack_B') }),
+  }),
   enemy_10081_mpplai: Object.freeze({
     translator_fuchou: Object.freeze({ change: 'A_Die_B', roles: clipSet('B_Idle', 'B_Move', 'B_Die', 'B_Attack') }),
     translator_youling: Object.freeze({ change: 'A_Die_C', roles: clipSet('C_Idle', 'C_Move', 'C_Die') }),
@@ -600,6 +612,8 @@ export class UnitView {
         if (this.flags & UF.SKILL) this.actor.setSkill(true);
         this.actor.setBase(this._baseFromAnim());
         if (deployed != null) { this.actor.deploy(); if (deployed > 0) this.actor.update(deployed); }
+        // a stealth-driven form (STEALTH_FORMS): the pose of the clip set in force now, even under a frozen stun
+        if (STEALTH_FORMS[id]) this.actor.syncFormPose();
       }
     }, () => {
       if (req === this._spineReq) { this._spineBusy = false; this._stuckAt = 0; }
@@ -747,6 +761,17 @@ export class UnitView {
     const prevFlags = this.flags;
     this.flags = s.flags | 0;
     this.anim = s.anim | 0;
+    // a stealth-driven form (STEALTH_FORMS: 假想敌：骨刺) follows this snapshot's stealth bit at once — before a DIE in the
+    // same snapshot, so it dies in the form it had
+    const stealthForm = this.isEnemy && this.alive ? STEALTH_FORMS[this.info.spine || this.info.defId] : null;
+    if (stealthForm) {
+      const form = this.flags & UF.STEALTH ? null : stealthForm;
+      if (form !== this.form) {
+        this.setForm(form);
+        this.actor?.syncFormPose();
+        if (this.imp) this.imp.dirty = true;
+      }
+    }
     if (this.isEnemy && Math.abs(s.vx) > 0.08) this.visFacing = s.vx < 0 ? -1 : 1;
     if ((prevFlags ^ this.flags) & UF.SKILL) this.setSkill(!!(this.flags & UF.SKILL));
     if (this.anim === ANIM.DIE && this.alive) this.die();