fix: 修复删除确认弹窗中红色按钮文字不可见问题

将 --destructive-foreground 颜色从红色改为白色，使红色删除按钮上的文字清晰可见。

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

web/src/style.css

@@ -23,7 +23,7 @@
   --accent: oklch(0.97 0 0);
   --accent-foreground: oklch(0.205 0 0);
   --destructive: oklch(0.577 0.245 27.325);
-  --destructive-foreground: oklch(0.577 0.245 27.325);
+  --destructive-foreground: oklch(1 0 0);
   --border: oklch(0.922 0 0);
   --input: oklch(0.922 0 0);
   --ring: oklch(0.708 0 0);