fix: 电池数字改为白字+黑色描边

黑字在黑色背景上看不见，白字在绿色填充上也不清楚
改用白色填充+黑色描边，在任何背景上都清晰可读

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

app/src/main/java/com/xiaoqu/watch/ui/widget/StatusBarView.kt

@@ -116,17 +116,24 @@ class StatusBarView @JvmOverloads constructor(
         canvas.drawRoundRect(fillRect, 2f, 2f, paint)
 
         // 电池内部文字：充电时显示 ⚡，否则显示百分比
-        // 深色文字确保在任何填充色上都清晰可读
+        // 白色文字 + 黑色描边，在填充条和黑色背景上都清晰
         if (batteryLevel >= 0) {
             val text = if (isCharging) "⚡" else "${batteryLevel}"
-            paint.style = Paint.Style.FILL
-            paint.color = 0xFF000000.toInt()
             paint.textSize = 11f
             paint.textAlign = Paint.Align.CENTER
             paint.typeface = android.graphics.Typeface.DEFAULT_BOLD
             val metrics = paint.fontMetrics
             val baselineY = centerY - (metrics.ascent + metrics.descent) / 2
-            canvas.drawText(text, startX + shellW / 2, baselineY, paint)
+            val cx = startX + shellW / 2
+            // 先画黑色描边（让白字在绿色填充上有边界）
+            paint.style = Paint.Style.STROKE
+            paint.strokeWidth = 2.5f
+            paint.color = 0xFF000000.toInt()
+            canvas.drawText(text, cx, baselineY, paint)
+            // 再画白色填充
+            paint.style = Paint.Style.FILL
+            paint.color = 0xFFFFFFFF.toInt()
+            canvas.drawText(text, cx, baselineY, paint)
             paint.textAlign = Paint.Align.LEFT
             paint.typeface = android.graphics.Typeface.DEFAULT
         }