feat(gui): +/- 按钮文本替换为 QtAwesome 图标，fa5s 统一升级为 fa6s

- ALSettingsWidget: BrowseQssButton/RemoveThemeButton 的 + / - 文本改为 fa6s.plus/fa6s.minus 图标
- ALAutoScriptEditDialog: ZoomInBtn/ZoomOutBtn 的全角 ＋/－ 改为 fa6s.plus/fa6s.minus 图标
- 其余图标同步从 fa5s 升级至 fa6s (Font Awesome 6)

Co-Authored-By: Claude <noreply@anthropic.com>

src/gui/ALAutoScriptEditDialog.py

@@ -211,12 +211,16 @@ class ALAutoScriptEditDialog(QDialog):
         Layout.setSpacing(3)
         Layout.setContentsMargins(3, 3, 3, 3)
         ToolbarLayout = QHBoxLayout()
-        self.ZoomInBtn = QPushButton("＋")
+        self.ZoomInBtn = QPushButton("")
+        self.ZoomInBtn.setIcon(qta.icon("fa6s.plus", color=self._iconColor()))
+        self.ZoomInBtn.setIconSize(QSize(14, 14))
         self.ZoomInBtn.setFixedSize(25, 25)
-        self.ZoomOutBtn = QPushButton("－")
+        self.ZoomOutBtn = QPushButton("")
+        self.ZoomOutBtn.setIcon(qta.icon("fa6s.minus", color=self._iconColor()))
+        self.ZoomOutBtn.setIconSize(QSize(14, 14))
         self.ZoomOutBtn.setFixedSize(25, 25)
         self.ZoomResetBtn = QPushButton("")
-        self.ZoomResetBtn.setIcon(qta.icon("fa5s.undo", color=self._iconColor()))
+        self.ZoomResetBtn.setIcon(qta.icon("fa6s.rotate-left", color=self._iconColor()))
         self.ZoomResetBtn.setIconSize(QSize(14, 14))
         self.ZoomResetBtn.setFixedSize(25, 25)
         self.ZoomResetBtn.setToolTip("重置缩放")
@@ -241,7 +245,7 @@ class ALAutoScriptEditDialog(QDialog):
         ToolbarLayout.addWidget(self.ZoomLabel)
         ToolbarLayout.addStretch()
         self.CopyBtn = QPushButton("")
-        self.CopyBtn.setIcon(qta.icon("fa5s.copy", color=self._iconColor()))
+        self.CopyBtn.setIcon(qta.icon("fa6s.copy", color=self._iconColor()))
         self.CopyBtn.setIconSize(QSize(14, 14))
         self.CopyBtn.setFixedSize(25, 25)
         self.CopyBtn.setToolTip("复制脚本")