feat: 二维码添加圆角效果

使用 Canvas + PorterDuff 裁剪，6%圆角半径

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src/main/java/com/xiaoqu/watch/ui/bind/BindFragment.kt

@@ -86,10 +86,11 @@ class BindFragment : BaseFragment<FragmentBindBinding>() {
         }
     }
 
-    /** 将 ZXing BitMatrix 转换为 Android Bitmap */
+    /** 将 ZXing BitMatrix 转换为圆角 Android Bitmap */
     private fun bitMatrixToBitmap(matrix: BitMatrix): Bitmap {
         val width = matrix.width
         val height = matrix.height
+        // 先生成方形 Bitmap
         val pixels = IntArray(width * height)
         for (y in 0 until height) {
             for (x in 0 until width) {
@@ -100,7 +101,20 @@ class BindFragment : BaseFragment<FragmentBindBinding>() {
                 }
             }
         }
-        return Bitmap.createBitmap(pixels, width, height, Bitmap.Config.ARGB_8888)
+        val squareBitmap = Bitmap.createBitmap(pixels, width, height, Bitmap.Config.ARGB_8888)
+
+        // 绘制圆角
+        val output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
+        val canvas = android.graphics.Canvas(output)
+        val paint = android.graphics.Paint(android.graphics.Paint.ANTI_ALIAS_FLAG)
+        val rect = android.graphics.RectF(0f, 0f, width.toFloat(), height.toFloat())
+        val radius = width * 0.06f  // 6% 圆角
+        canvas.drawRoundRect(rect, radius, radius, paint)
+        paint.xfermode = android.graphics.PorterDuffXfermode(android.graphics.PorterDuff.Mode.SRC_IN)
+        canvas.drawBitmap(squareBitmap, 0f, 0f, paint)
+        squareBitmap.recycle()
+
+        return output
     }
 
     /**