feat(ui): 弹层进出场过渡 + 首屏暖深色英雄（P2-6/P4-6）

- useMountTransition hook（延迟卸载播放退场，尊重 reduced-motion）+ vitest
- Drawer 淡入+滑入进出场；focus/scroll-lock 仍由 open 驱动、focus 键 shouldRender 防丢首焦
- Toast 入场 toast-in 动画（motion-safe）
- P4-6 首屏零作品用 callout 暖深色编辑部英雄（对标 cta-band-dark，不干扰工作库）
  新增 callout/on-callout/on-callout-soft 双主题成对 token

apps/web/components/Drawer.tsx

@@ -7,8 +7,12 @@ import { Button } from "@/components/ui/Button";
 import { handleTabTrap } from "@/lib/a11y/focusTrap";
 import { useRestoreFocus } from "@/lib/a11y/useRestoreFocus";
 import { useBodyScrollLock } from "@/lib/ui/useBodyScrollLock";
+import { useMountTransition } from "@/lib/ui/useMountTransition";
 import { overlayScrim } from "@/lib/ui/variants";
 
+// 抽屉进出场时长（与 --dur-base 一致）。
+const DRAWER_MS = 180;
+
 interface DrawerProps {
   open: boolean;
   onClose: () => void;
@@ -36,11 +40,15 @@ export function Drawer({
   const panelRef = useRef<HTMLDivElement>(null);
   const closeRef = useRef<HTMLButtonElement>(null);
 
+  const { shouldRender, isVisible } = useMountTransition(open, DRAWER_MS);
+
   useBodyScrollLock(open);
   useRestoreFocus(open, triggerRef);
 
   useEffect(() => {
-    if (!open) return;
+    // 面板真正挂载（shouldRender）且处于打开态时才装监听/落焦——
+    // 因进出场延迟了卸载，若仅依赖 open 会错过挂载帧导致首焦点丢失。
+    if (!open || !shouldRender) return;
     const onKey = (e: KeyboardEvent): void => {
       if (e.key === "Escape") {
         e.preventDefault();
@@ -51,14 +59,25 @@ export function Drawer({
     // 焦点陷阱首焦点落在具名关闭按钮上（而非整个面板）。
     closeRef.current?.focus();
     return () => window.removeEventListener("keydown", onKey);
-  }, [open, onClose]);
+  }, [open, shouldRender, onClose]);
 
-  if (!open) return null;
+  if (!shouldRender) return null;
 
   const sideClass = side === "left" ? "left-0 border-r" : "right-0 border-l";
+  const slideClass =
+    side === "left"
+      ? isVisible
+        ? "translate-x-0"
+        : "-translate-x-full"
+      : isVisible
+        ? "translate-x-0"
+        : "translate-x-full";
 
   return (
-    <div className={`${overlayScrim} lg:hidden`} onClick={onClose}>
+    <div
+      className={`${overlayScrim} lg:hidden motion-safe:transition-opacity motion-safe:duration-base ${isVisible ? "opacity-100" : "opacity-0"}`}
+      onClick={onClose}
+    >
       <div
         ref={panelRef}
         id={id}
@@ -70,7 +89,7 @@ export function Drawer({
           // focus trap：Tab/Shift+Tab 在抽屉内循环，不逃逸到背景（WCAG 2.1.2）。
           if (panelRef.current) handleTabTrap(panelRef.current, e);
         }}
-        className={`absolute top-0 h-full w-64 max-w-[80vw] overflow-auto overscroll-contain border-line bg-panel py-4 shadow-paper outline-none ${sideClass}`}
+        className={`absolute top-0 h-full w-64 max-w-[80vw] overflow-auto overscroll-contain border-line bg-panel py-4 shadow-paper outline-none motion-safe:transition-transform motion-safe:duration-base ease-standard ${sideClass} ${slideClass}`}
       >
         <div className="mb-2 flex justify-end px-2">
           <Button