=== WL-816j2 ④ 마지막 조율 (PD 구도 1280×720) ===

1) 무늬 선 3단 — LightColor + FoamShadowColor(무늬의 어두운 쪽). 목표 = 데모(σ 0.0024)에 가깝게
   Light RGBA(0.450, 0.740, 0.860, 1.000) Shadow RGBA(0.780, 0.860, 0.920, 1.000) σ=0.0552 · 거품 1.16% #F9F5F9(R−B 0) → Screenshots_WL/WL816j2/h_soft1.png
   Light RGBA(0.420, 0.720, 0.845, 1.000) Shadow RGBA(0.930, 0.960, 0.980, 1.000) σ=0.0515 · 거품 1.14% #F9F5F9(R−B 0) → Screenshots_WL/WL816j2/h_soft2.png
   Light RGBA(0.385, 0.705, 0.830, 1.000) Shadow RGBA(1.000, 1.000, 1.000, 1.000) σ=0.0488 · 거품 1.20% #F9F4F8(R−B 1) → Screenshots_WL/WL816j2/h_soft3.png

2) 띠 폭 3단 + 폭별 비용 (60프레임 × 2회)
   [띠 off] σ=0.0525 · 거품 1.13% #FCF2F3(R−B 9) → Screenshots_WL/WL816j2/i_w0_off.png · 0.858 ms
   [폭 0.9 m · 삼각형 744] σ=0.0517 · 거품 1.16% #FCF1F3(R−B 9) → Screenshots_WL/WL816j2/i_w1.png · 0.840 / 0.867 ms
   [폭 1.6 m · 삼각형 1280] σ=0.0508 · 거품 1.22% #FBF4F7(R−B 4) → Screenshots_WL/WL816j2/i_w2.png · 0.878 / 0.882 ms
   [폭 2.6 m · 삼각형 1864] σ=0.0502 · 거품 2.34% #F3EFFB(R−B -8) → Screenshots_WL/WL816j2/i_w3.png · 0.888 / 0.848 ms

3) 최종 전/후 (PD 구도)
   [전] main(물 D · 띠 없음) σ=0.0820 · 거품 10.16% #ECDAE7(R−B 5) → Screenshots_WL/WL816j2/z_before_pd.png
   [후] 816j2(물 E · 띠 on) σ=0.0473 · 거품 1.14% #FBF3F6(R−B 5) → Screenshots_WL/WL816j2/z_after_pd.png