fix: improve text color contrast in dark mode

- Change NodeView text from hardcoded black to primaryText color
- Add secondaryText color to comment count labels for better visibility
- Add Appearance Settings option to Settings page menu

Author: graycreate

V2er/View/Feed/FeedItemView.swift

@@ -37,6 +37,7 @@ struct FeedItemView<Data: FeedItemProtocol>: View {
                 .padding(.vertical, 4)
             Text("评论\(data.replyNum.safe)")
                 .font(.footnote)
+                .foregroundColor(.secondaryText)
                 .greedyWidth(.trailing)
         }
         .padding(12)

V2er/View/Settings/SettingsPage.swift

@@ -22,8 +22,11 @@ struct SettingsPage: View {
   private var formView: some View {
     ScrollView {
       VStack(spacing: 0) {
-        SectionItemView("通用设置", showDivider: false)
+        SectionItemView("外观设置", showDivider: false)
           .padding(.top, 8)
+          .to { AppearanceSettingView() }
+        
+        SectionItemView("通用设置")
           .to { OtherSettingsView() }
 
           SectionItemView("帮助与反馈")

V2er/View/Widget/NodeView.swift

@@ -25,7 +25,7 @@ struct NodeView: View {
         } label: {
             Text(name)
                 .font(.footnote)
-                .foregroundColor(.black)
+                .foregroundColor(.primaryText)
                 .lineLimit(1)
                 .padding(.horizontal, 14)
                 .padding(.vertical, 8)