新增: 设置页 UX 重构(master-detail 左导航 + 搜索 + 即时反馈 + 导入导出)

- SettingsNav 左导航 7 类 + 顶部搜索(索引匹配 label/desc 高亮定位)
- GeneralPanel 拆分 Appearance/Performance/Advanced Section
- SettingRow 统一行 + 即时反馈(已保存)+ 下轮生效 badge
- 统一组件库 settings.css(scoped 重复 class 抽全局)
- 导入导出(默认排除 keyring 密钥)
- activeCategory 持久化 + 窄屏折叠 tab

src/components/settings/settings.css

@@ -0,0 +1,69 @@
+/* DevFlow 设置统一组件库(UX 重构阶段1)
+   各 Panel scoped 副本抽取到全局,消除 panel/setting 系列/toggle/btn 5/5+3/5 重复。
+   来源基准:GeneralPanel/KnowledgePanel scoped(已确认 CSS 一致)。
+   各 Panel scoped 仅保留特有样式:provider-card/dir-row/connection-card 等。 */
+
+/* ===== 面板容器(5/5 Panel 重复) ===== */
+.panel {
+  background: var(--df-bg-card);
+  border: 0.5px solid var(--df-border);
+  border-radius: var(--df-radius-lg);
+  padding: var(--df-pad-panel);
+}
+.panel-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: var(--df-gap-head);
+}
+.panel-header h2 { font-size: 15px; font-weight: 500; }
+
+/* ===== 设置行容器(表单型 Panel 共用) ===== */
+.general-settings { display: flex; flex-direction: column; }
+.setting-row {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 14px 0;
+  border-bottom: 0.5px solid var(--df-border);
+}
+.setting-row:last-child { border-bottom: none; }
+.setting-info { display: flex; flex-direction: column; gap: 2px; }
+.setting-label { font-size: 14px; font-weight: 500; color: var(--df-text); }
+.setting-desc { font-size: 12px; color: var(--df-text-dim); }
+.setting-control { display: flex; align-items: center; }
+
+/* ===== 控件(5/5 Panel 重复) ===== */
+.setting-select {
+  padding: 6px 12px;
+  background: var(--df-bg);
+  border: 0.5px solid var(--df-border);
+  border-radius: var(--df-radius-sm);
+  color: var(--df-text);
+  font-size: 13px;
+  outline: none;
+  cursor: pointer;
+  min-width: 160px;
+}
+.setting-select:focus { border-color: var(--df-accent); }
+
+/* Toggle(3/5 Panel 重复) */
+.toggle { position: relative; display: inline-block; width: 40px; height: 22px; cursor: pointer; }
+.toggle input { opacity: 0; width: 0; height: 0; }
+.toggle-slider { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: var(--df-border); border-radius: var(--df-radius-lg); transition: background 0.2s; }
+.toggle-slider::before { content: ''; position: absolute; width: 16px; height: 16px; left: 3px; bottom: 3px; background: var(--df-text-dim); border-radius: 50%; transition: transform 0.2s, background 0.2s; }
+.toggle input:checked + .toggle-slider { background: var(--df-accent); }
+.toggle input:checked + .toggle-slider::before { transform: translateX(18px); background: #fff; }
+
+/* ===== 按钮(原 Settings.vue,列表型 Panel 共用) ===== */
+.btn { padding: 8px 16px; border: none; border-radius: var(--df-radius-sm); font-size: 13px; cursor: pointer; transition: all 0.15s; }
+.btn-primary { background: var(--df-accent); color: #fff; }
+.btn-primary:hover { background: var(--df-accent-hover); }
+.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }
+.btn-ghost { background: transparent; color: var(--df-text-secondary); border: 0.5px solid var(--df-border); }
+.btn-ghost:hover { background: var(--df-bg-card); color: var(--df-text); }
+.btn-ghost:disabled { opacity: 0.5; cursor: not-allowed; }
+.btn-sm { padding: 4px 12px; font-size: 12px; }
+
+/* ===== 空提示(列表型 Panel 共用) ===== */
+.empty-hint { color: var(--df-text-dim); font-size: 13px; padding: 16px 0; text-align: center; }