아바타 v3 표현 엔진·리노컷 렌더러·립싱크와 Lab

- 표현 엔진: 채널 34개(mouthRound 추가), 표정 28종·강도 곡선·반응 클립 26종·지문 cue, 미세표정 누설
- 발화층: 한글 자모 비짐 9종, TTS 오디오 선분석 정렬, 60ms 앞당김·모음 간 비닫힘
- 발화 동반층: 억양·강세에 맞춘 고개 표류·끄덕임·질문 갸웃·들숨·눈썹 박·시선 회피·쉼 깜빡임
- P1 서연 리노컷 렌더러: 원화 픽셀 입술 띠 변형, 하관 띠 변형(턱·코 들썩), 볼 불룩, 작은 크기 선 보정, 모티프·배경 색면
- /dev/avatar-lab, check:avatar-presets·check:avatar-lipsync, avatar-lab E2E 19개

apps/web/src/components/avatar/engine/clipPlayer.ts

@@ -0,0 +1,78 @@
+/* =====================================================================
+   아바타 v3 반응 클립 재생기 — 결정문 §6.1 키프레임 보간·엔벨로프·합성.
+   순수 함수뿐이다. 시간은 인자로만 받는다.
+   ===================================================================== */
+
+import { mirrorDelta, type ChannelDelta, type ChannelId } from "./channels";
+import type { ClipEase, Keyframe, ReactionClip } from "./clipCatalog";
+
+function ease(kind: ClipEase, t: number): number {
+  switch (kind) {
+    case "in":
+      return t * t;
+    case "out":
+      return 1 - (1 - t) * (1 - t);
+    case "inOut":
+      return 3 * t * t - 2 * t * t * t;
+    case "hold":
+      return t >= 1 ? 1 : 0;
+    case "linear":
+    default:
+      return t;
+  }
+}
+
+function sampleTrack(frames: readonly Keyframe[], tMs: number): number {
+  const first = frames[0];
+  if (tMs <= first[0]) return first[1];
+  const last = frames[frames.length - 1];
+  if (tMs >= last[0]) return last[1];
+  for (let i = 1; i < frames.length; i++) {
+    const [t1, v1, arrivalEase] = frames[i];
+    if (tMs > t1) continue;
+    const [t0, v0] = frames[i - 1];
+    const span = t1 - t0;
+    const localT = span <= 0 ? 1 : (tMs - t0) / span;
+    const eased = ease(arrivalEase ?? "linear", localT);
+    return v0 + (v1 - v0) * eased;
+  }
+  return last[1];
+}
+
+/** 클립의 tMs 시점 채널 delta(가산값). t가 구간 밖이면 빈 delta. */
+export function sampleClip(clip: ReactionClip, tMs: number): ChannelDelta {
+  if (tMs < 0 || tMs > clip.durationMs) return {};
+  const out: ChannelDelta = {};
+  for (const id of Object.keys(clip.tracks) as ChannelId[]) {
+    const frames = clip.tracks[id];
+    if (!frames || frames.length === 0) continue;
+    out[id] = sampleTrack(frames, tMs);
+  }
+  return out;
+}
+
+/** fadeIn→hold→fadeOut 엔벨로프(0..1). 구간 밖은 0. */
+export function envelope(clip: ReactionClip, tMs: number): number {
+  if (tMs < 0 || tMs > clip.durationMs) return 0;
+  const { fadeInMs, fadeOutMs, durationMs } = clip;
+  if (fadeInMs > 0 && tMs < fadeInMs) return tMs / fadeInMs;
+  const fadeOutStart = durationMs - fadeOutMs;
+  if (fadeOutMs > 0 && tMs > fadeOutStart) return (durationMs - tMs) / fadeOutMs;
+  return 1;
+}
+
+export interface ResolveClipOptions {
+  weight?: number;
+  mirror?: boolean;
+}
+
+/** sampleClip × envelope × weight, mirror면 좌우 반전까지 적용한 최종 delta. */
+export function resolveClipDelta(clip: ReactionClip, tMs: number, opts: ResolveClipOptions = {}): ChannelDelta {
+  const raw = sampleClip(clip, tMs);
+  const scale = envelope(clip, tMs) * (opts.weight ?? 1);
+  const out: ChannelDelta = {};
+  for (const id of Object.keys(raw) as ChannelId[]) {
+    out[id] = (raw[id] as number) * scale;
+  }
+  return opts.mirror ? mirrorDelta(out) : out;
+}