补上组织架构部门蓝色高亮修复遗漏的CSS改动（.expanded重命名为.me）

上一个commit(1d47c586)只提交了JSX那部分（DeptRow/DeptNode改用containsMe），
对应的CSS改名（.organization-department.expanded → .me）当时被同一文件里
其他并发改动的暂存操作顶掉了，没有一起进去，导致上一commit单看JSX是完整的，
但CSS选择器名字还没改，实际不生效。这里补上，两个commit合起来才是完整修复。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

css/base.css

@@ -1590,11 +1590,18 @@
   font-size: 1.3rem;
 }
 
-.organization-department.expanded {
+/* Renamed from .expanded -- this rule drives the blue "this is my department" highlight from
+   docs/images/部门组织框架.png (only the department the current user directly belongs to, e.g.
+   "技术4人" in the reference, not every expanded node -- the reference's always-expanded root
+   "总裁办50人" stays plain black). Was keyed off the same class as the expand/collapse chevron
+   state, which colored ANY expanded department blue including the root, on every page load, with
+   nothing to do with where the current user actually is -- see workplace-collaboration-view.jsx's
+   DeptRow/DeptNode comments for the live repro (via stub data, this tenant's real org tree is empty). */
+.organization-department.me {
   color: #2094f3;
 }
 
-.organization-department.expanded > .material-icons:first-child {
+.organization-department.me > .material-icons:first-child {
   color: #2094f3;
 }