fix(ui): 修复 .ui XML 标签嵌套错误

- AppearancePageSpacer 从 CustomQssGroupBoxLayout 内移出，恢复为 AppearancePageLayout 的直接子项
- 补全缺失的 AppearancePageLayout 与 QScrollArea 闭合标签
- 修复 alignment 属性的 <set> 标签未正确闭合

src/gui/ALSettingsWidget.py

@@ -251,11 +251,9 @@ class ALSettingsWidget(QWidget, Ui_ALSettingsWidget):
             need_theme = t.get("need_theme", "both")
             brief = t.get("brief", "没有相关简介")
             self.ThemeInfoLabel.setText(
-                f"<b>{name}</b>"
-                f" - 适用于 <i>{_themeToReadable(need_theme)}</i> 主题<br>"
-                f"<span style='font-size:smaller;'>"
-                f"作者：{author}<br>"
-                f"{brief}</span>"
+                f"<b>{name}</b> - 适用于 <i>{_themeToReadable(need_theme)}</i> 主题<br>"
+                f"作者：{author}<br><br>"
+                f"{brief}"
             )
         else:
             self.ThemeInfoLabel.setText("")

src/gui/resources/ui/ALSettingsWidget.ui

@@ -349,7 +349,7 @@
              <enum>Qt::TextFormat::RichText</enum>
             </property>
             <property name="alignment">
-             <set>Qt::AlignmentFlag::AlignLeading|Qt::AlignmentFlag::AlignTop</property>
+             <set>Qt::AlignmentFlag::AlignLeading|Qt::AlignmentFlag::AlignTop</set>
             </property>
             <property name="wordWrap">
              <bool>true</bool>
@@ -415,28 +415,28 @@
             </property>
            </widget>
           </item>
-          <item>
-           <spacer name="AppearancePageSpacer">
-            <property name="orientation">
-             <enum>Qt::Orientation::Vertical</enum>
-            </property>
-            <property name="sizeHint" stdset="0">
-             <size>
-              <width>20</width>
-              <height>40</height>
-             </size>
-            </property>
-           </spacer>
-          </item>
          </layout>
         </widget>
        </item>
-        </layout>
-       </widget>
+       <item>
+        <spacer name="AppearancePageSpacer">
+         <property name="orientation">
+          <enum>Qt::Orientation::Vertical</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>40</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       </layout>
       </widget>
-     </item>
-    </layout>
-   </item>
+     </widget>
+    </item>
+   </layout>
+  </item>
    <item>
     <layout class="QHBoxLayout" name="ButtonLayout">
      <property name="spacing">