优化: UI/UX 走查修复与跨模块样式统一治理

- 前四批:暗色 UA 重置+color-scheme、知识详情窄屏双闸、启动链 6 点加固、原生 tooltip 换 CSS
- 统一治理:新建 --df-pad-page/--df-fs-item/--df-on-accent token 与 .df-seg/.modal-box--sm--md/.df-badge--solid/.empty-icon--sm--xs 公共类
- 收编:status-tag 双规格、AuditLog 容器、模态自建块、空态图标四档、加载更多三实现、圆角/字号/mono 栈字面量约 60 处
- 根修:.page-header h1 加压缩保护(治标题竖排);KnowledgeDetail hover token 笔误

src/components/project/FileExplorer.vue

@@ -116,7 +116,7 @@
             <span class="spinner"></span>
           </div>
           <div v-else-if="!currentModuleId" class="module-empty">
-            <div class="module-empty-icon">📦</div>
+            <div class="empty-icon empty-icon--xs">📦</div>
             <p class="module-empty-hint">{{ $t('projectDetail.modulesEmptyHint') }}</p>
             <div class="module-empty-actions">
               <button class="btn btn-primary btn-sm" type="button" @click="openAddModule">{{ $t('fileExplorer.addModule') }}</button>
@@ -701,7 +701,7 @@ async function onRemoveModule() {
 .crumb {
   cursor: pointer;
   padding: 2px 6px;
-  border-radius: 4px;
+  border-radius: var(--df-radius-sm);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
@@ -789,7 +789,7 @@ async function onRemoveModule() {
   min-width: 14px;
   height: 14px;
   padding: 0 4px;
-  border-radius: 6px;
+  border-radius: var(--df-radius);
   background: var(--df-accent);
   color: #fff;
   font-size: 9px;
@@ -835,11 +835,7 @@ async function onRemoveModule() {
   height: 100%;
   justify-content: center;
 }
-.module-empty-icon {
-  font-size: 28px;
-  opacity: 0.6;
-  line-height: 1;
-}
+/* 空态图标走 global .empty-icon.empty-icon--xs(28px 档,scoped 28px 副本已删) */
 .module-empty-hint {
   margin: 0;
   font-size: 12px;