fix: 大小王角标不显示 & 导出整副牌失效

frontend/src/utils/cardRenderer.js

@@ -316,16 +316,25 @@ async function drawJokerBody(ctx, w, h, which, design, project) {
   const labelSize = Math.max(20, Math.round(w * 0.06))
   const textSize  = Math.max(16, Math.round(w * 0.045))
   const pad = Math.max(10, w * 0.04)
+
+  // 左上角标
   ctx.font = `bold ${labelSize}px ${design.font_family || 'Times New Roman'}, serif`
   ctx.fillText('JOKER', pad, pad)
   ctx.fillText(label, pad, pad + textSize + 4)
-  // 右下：旋转 180° 平移
+
+  // 右下角标
+  ctx.save()
   ctx.translate(w - pad, h - pad)
   ctx.rotate(Math.PI)
+  ctx.fillStyle = '#FFFFFF'
+  ctx.textAlign = 'left'
+  ctx.textBaseline = 'top'
   ctx.font = `bold ${labelSize}px ${design.font_family || 'Times New Roman'}, serif`
   ctx.fillText('JOKER', 0, 0)
   ctx.fillText(label, 0, textSize + 4)
   ctx.restore()
+
+  ctx.restore()
 }
 
 async function drawBackSide(ctx, w, h, design, project) {