左侧菜单改版：工作台下拉 + 5个图标导航

- 工作台改为下拉菜单（layout-grid + chevron-down 图标）
- 顶部 tabs 移到左侧 sidebar，5 个图标导航（首页/财务/台账/方案/产品）
- 头像与工作台间、工作台与导航间各加分隔线
- 经营管理 tab 短名改为'财务'
- 移除 .tabs 样式，新增 .sidebar-tab 样式

static/modules/projects.js

@@ -13,13 +13,57 @@ function applyUserTenants() {
       e.stopPropagation();
       toggleUserMenu(user);
     });
-    const allowedTenants = data.tenants || [];
-    document.querySelectorAll(".workspace-nav-item").forEach(el => {
-      el.style.display = allowedTenants.includes(el.dataset.tenant) ? "" : "none";
-    });
+    // 缓存可用工作台列表，供下拉菜单使用
+    state.allowedTenants = data.tenants || [];
+    updateTenantLabel();
   });
 }
 
+window.toggleTenantMenu = (event) => {
+  event.stopPropagation();
+  let menu = document.getElementById("tenantMenu");
+  if (menu) { menu.remove(); return; }
+  const btn = event.currentTarget;
+  const rect = btn.getBoundingClientRect();
+  const tenants = state.allowedTenants || [];
+  menu = document.createElement("div");
+  menu.id = "tenantMenu";
+  menu.className = "fixed bg-white rounded-lg shadow-xl border border-slate-200 py-1 min-w-[160px] z-[9999]";
+  menu.style.left = Math.min(rect.left - 8, window.innerWidth - 180) + "px";
+  menu.style.top = rect.bottom + 6 + "px";
+  menu.innerHTML = `
+    <div class="px-4 py-2 border-b border-slate-100">
+      <p class="text-xs font-semibold text-slate-500 uppercase tracking-wider">切换工作台</p>
+    </div>
+    ${tenants.map(t => `
+      <button class="w-full text-left px-4 py-2 text-sm hover:bg-slate-50 transition-colors flex items-center justify-between gap-2 ${t === state.tenant ? 'text-blue-600 font-medium' : 'text-slate-700'}" onclick="switchTenantFromMenu('${t.replace(/'/g, "\\'")}')">
+        <span>${esc(t)}</span>
+        ${t === state.tenant ? '<i data-lucide="check" style="width:14px;height:14px"></i>' : ''}
+      </button>
+    `).join('')}`;
+  document.body.appendChild(menu);
+  if (window.lucide) lucide.createIcons();
+  setTimeout(() => {
+    document.addEventListener("click", function closeMenu() {
+      menu.remove();
+      document.removeEventListener("click", closeMenu);
+    }, { once: true });
+  }, 10);
+};
+
+window.switchTenantFromMenu = (tenant) => {
+  document.getElementById("tenantMenu")?.remove();
+  switchTenant(tenant);
+};
+
+function updateTenantLabel() {
+  const label = document.querySelector("#currentTenantLabel");
+  if (label) {
+    label.textContent = state.tenant.replace("·无界", "") || "工作台";
+    label.title = state.tenant;
+  }
+}
+
 window.toggleUserMenu = (user) => {
   let menu = document.getElementById("userMenu");
   if (menu) { menu.remove(); return; }

static/modules/utils.js

@@ -123,7 +123,7 @@ async function load() {
 function switchTab(tab) {
   state.active = tab;
   localStorage.setItem("opc-active-tab", tab);
-  document.querySelectorAll("#tabs button").forEach((btn) => btn.classList.toggle("active", btn.dataset.tab === tab));
+  document.querySelectorAll(".sidebar-tab").forEach((btn) => btn.classList.toggle("active", btn.dataset.tab === tab));
   document.querySelectorAll(".panel").forEach((panel) => panel.classList.toggle("active", panel.id === tab));
   render();
 }
@@ -179,7 +179,8 @@ window.switchTenant = (tenant) => {
   state.selectedProject = null;
   localStorage.setItem("opc-active-tenant", tenant);
   document.querySelector("#workspaceTitle").textContent = tenant.replace("·无界", "") + " OPC 工作台";
-  document.querySelectorAll(".workspace-nav-item").forEach((el) => el.classList.toggle("active", el.dataset.tenant === tenant));
+  const label = document.querySelector("#currentTenantLabel");
+  if (label) { label.textContent = tenant.replace("·无界", "") || "工作台"; label.title = tenant; }
   load();
 };
 window.doLogout = async () => {