feat: Live2D outfit textures + expression system + canvas tweaks

- Generated 5 outfit texture variants via HSL recolor (saved skin tones)
- Dynamic texture_02 swapping when outfit changes
- Expression buttons (Normal, Smile, Sad, Angry, Surprised, Blushing)
- Random idle expression changes every 8-15s
- Responsive canvas sizing with devicePixelRatio support
- Outfit generation script in scripts/gen_outfits.py
- Smoother lip-sync with phase-based mouth animation

scripts/gen_outfits.py

@@ -0,0 +1,88 @@
+#!/usr/bin/env python3
+"""Generate recolored outfit textures for Kira's Live2D model.
+
+Takes the base texture_02.png (clothing layer) and creates
+color variants for each outfit using HSL shifts on non-skin areas.
+"""
+
+from PIL import Image
+import colorsys
+import os
+
+BASE_DIR = os.path.expanduser(
+    "~/Projects/ai-body-double/frontend/public/live2d/models/kira"
+)
+TEXTURE_DIR = os.path.join(BASE_DIR, "Epsilon.1024")
+OUT_DIR = os.path.join(BASE_DIR, "outfits")
+
+# Outfit → HSL shift mapping (hue_shift_deg, sat_mult, light_mult)
+# Applied to non-white, non-skin pixels
+OUTFITS = {
+    "cozy-hoodie":   (10,   1.1, 1.0),   # warm pink shift
+    "girly-dress":   (240,  1.2, 0.95),  # lavender/purple
+    "pajama-set":    (140,  0.8, 1.1),   # minty green
+    "study-sweater": (30,   1.1, 1.0),   # warm orange/amber
+    "going-out":     (320,  1.3, 1.05),  # bright pink/magenta
+}
+
+def is_skin(r, g, b):
+    """Roughly detect skin tones (avoid recoloring skin)."""
+    return 180 < r < 250 and 120 < g < 200 and 80 < b < 170
+
+def is_white_or_void(r, g, b, a):
+    """Detect transparent or near-white pixels."""
+    if a < 10:
+        return True
+    return r > 240 and g > 240 and b > 240
+
+def recolor_texture(src_path, dst_path, hue_shift, sat_mult, light_mult):
+    """Recolor a texture by shifting HSL on non-skin, non-white pixels."""
+    img = Image.open(src_path).convert("RGBA")
+    pixels = img.load()
+    w, h = img.size
+
+    for y in range(h):
+        for x in range(w):
+            r, g, b, a = pixels[x, y]
+            if is_white_or_void(r, g, b, a) or is_skin(r, g, b):
+                continue
+
+            # Convert to HSL
+            h_val, l_val, s_val = colorsys.rgb_to_hls(r / 255, g / 255, b / 255)
+
+            # Apply shifts
+            h_val = (h_val + hue_shift / 360) % 1.0
+            s_val = min(1.0, s_val * sat_mult)
+            l_val = max(0, min(1.0, l_val * light_mult))
+
+            # Convert back to RGB
+            nr, ng, nb = colorsys.hls_to_rgb(h_val, l_val, s_val)
+            pixels[x, y] = (int(nr * 255), int(ng * 255), int(nb * 255), a)
+
+    os.makedirs(os.path.dirname(dst_path), exist_ok=True)
+    img.save(dst_path)
+    size = os.path.getsize(dst_path)
+    print(f"  Created {os.path.basename(dst_path)} ({size//1024}KB)")
+
+
+def main():
+    src = os.path.join(TEXTURE_DIR, "texture_02.png")
+    if not os.path.exists(src):
+        print(f"Source not found: {src}")
+        return 1
+
+    print(f"Generating outfit textures from {src}")
+    print()
+
+    for outfit_name, (hue, sat, light) in OUTFITS.items():
+        dst = os.path.join(OUT_DIR, f"{outfit_name}.png")
+        print(f"  {outfit_name}: hue={hue}° sat={sat:.1f}x light={light:.2f}x")
+        recolor_texture(src, dst, hue, sat, light)
+
+    print()
+    print("Done! Texture variants ready.")
+    return 0
+
+
+if __name__ == "__main__":
+    exit(main())