feat(web): Field 标签自动关联控件 + 全局壳无障碍(skip link/设置可访问名/抽屉焦点归还)

apps/web/components/NavDrawer.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState } from "react";
+import { useRef, useState } from "react";
 import { Menu } from "lucide-react";
 
 import { Button } from "@/components/ui/Button";
@@ -16,10 +16,12 @@ interface NavDrawerProps {
 // 移动端导航：汉堡按钮 + 左侧抽屉（仅 <lg；桌面用 LeftNav 静态侧栏）。UX §5.1。
 export function NavDrawer({ projectId, activeNav }: NavDrawerProps) {
   const [open, setOpen] = useState(false);
+  const triggerRef = useRef<HTMLButtonElement>(null);
 
   return (
     <>
       <Button
+        ref={triggerRef}
         onClick={() => setOpen(true)}
         aria-label="打开导航"
         aria-expanded={open}
@@ -34,6 +36,7 @@ export function NavDrawer({ projectId, activeNav }: NavDrawerProps) {
         onClose={() => setOpen(false)}
         side="left"
         label="主导航"
+        triggerRef={triggerRef}
       >
         <NavItems
           projectId={projectId}