feat(wardrobe): swap Live2D outfit textures via wardrobe buttons

Epsilon model has 3 texture sheets: body (00), hair (01), clothes (02).
Outfit PNGs in /outfits/ replace texture_02 at runtime via PIXI BaseTexture swap.
Live2DStage now accepts outfit prop and swaps on change.
App passes currentOutfit to Live2DStage.

frontend/src/App.tsx

@@ -110,6 +110,7 @@ export default function App() {
         onKiraReady={(model) => { kiraModelRef.current = model; }}
         onReady={() => setLive2dReady(true)}
         isSpeaking={isKiraSpeaking}
+        outfit={currentOutfit}
       />
 
       <Particles type={currentScene.particles ?? 'none'} />

frontend/src/components/Live2DStage.tsx

@@ -4,6 +4,7 @@ interface Props {
   onKiraReady?: (model: any) => void;
   onReady?: () => void;
   isSpeaking?: boolean;
+  outfit?: string;
 }
 
 /**
@@ -46,8 +47,10 @@ function positionCat(cat: any) {
   cat.position.set(r.left + r.width / 2, r.top + r.height / 2 + 10);
 }
 
-export default function Live2DStage({ onKiraReady, onReady }: Props) {
+export default function Live2DStage({ onKiraReady, onReady, outfit }: Props) {
   const canvasRef = useRef<HTMLCanvasElement>(null);
+  const kiraModelRef = useRef<any>(null);
+  const clothTexIdxRef = useRef<number>(-1);
 
   useEffect(() => {
     let mounted = true;
@@ -96,6 +99,22 @@ export default function Live2DStage({ onKiraReady, onReady }: Props) {
         (kiraModel as any).isInteractive = () => false;
         app.stage.addChild(kiraModel as any);
 
+        kiraModelRef.current = kiraModel;
+
+        // Find the clothing texture index (texture_02 = the outfit sheet)
+        try {
+          const core = (kiraModel as any).internalModel?.coreModel;
+          if (core) {
+            const drawCount = core.getDrawableCount();
+            // texture_02 is the last texture, find which drawable uses it
+            // We'll swap the PIXI texture directly on the model's textures array
+            const textures = (kiraModel as any).internalModel?.textures;
+            if (textures && textures.length >= 3) {
+              clothTexIdxRef.current = 2; // texture_02 is the outfit
+            }
+          }
+        } catch {}
+
         try { kiraModel.motion('Idle'); } catch {}
         try { kiraModel.expression('Normal'); } catch {}
 
@@ -135,6 +154,42 @@ export default function Live2DStage({ onKiraReady, onReady }: Props) {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
+  // Outfit swap effect
+  useEffect(() => {
+    const model = kiraModelRef.current;
+    const texIdx = clothTexIdxRef.current;
+    if (!model || texIdx < 0 || !outfit) return;
+
+    const outfitSrc = `/live2d/models/kira/outfits/${outfit}.png`;
+    
+    const swapTexture = async () => {
+      try {
+        const textures = (model as any).internalModel?.textures;
+        if (!textures || !textures[texIdx]) return;
+        
+        const PIXI = await import('pixi.js');
+        const newBase = PIXI.BaseTexture.from(outfitSrc);
+        
+        const doSwap = () => {
+          if (newBase.valid) {
+            textures[texIdx].baseTexture = newBase;
+            textures[texIdx].update();
+          }
+        };
+        
+        if (newBase.valid) {
+          doSwap();
+        } else {
+          newBase.once('loaded', doSwap);
+        }
+      } catch (e) {
+        console.warn('[Live2DStage] outfit swap failed:', e);
+      }
+    };
+    
+    swapTexture();
+  }, [outfit]);
+
   return (
     <canvas
       ref={canvasRef}