fix: 阅读主题isDark跟随应用明暗设置而非背景亮度推导

app/src/main/java/io/legado/app/ui/book/read/ReadBookColorTheme.kt

@@ -87,7 +87,7 @@ private fun rememberReadBackgroundTheme(
         seedColor = sourceColor,
         backgroundColor = surfaceColor,
         containerColor = null,
-        fallbackDark = isAppDark,
+        deriveDarkFromColor = false,
         paletteStyle = paletteStyle,
     )
 }