style(storybook): group overlay, disclosure and navigation story pages

- Sheet + Drawer, Tooltip + Hover Card, Accordion + Collapsible,
  Dialog + Alert Dialog, Dropdown Menu + Context Menu on one page each
  (specimens moved to *-examples.tsx; absorbed Stories keep their IDs)
- Popover, Tabs content spacing, Breadcrumb, Menubar and Command tidied
- Component docs updated to the new representative pages

src/components/alert-dialog-examples.tsx

@@ -0,0 +1,64 @@
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+  Button,
+} from "@hm-design/ui"
+
+// Shared Alert Dialog specimens (Storybook only). Used by the Alert Dialog Stories (verification) and by the Dialog representative
+// page, which shows general and confirmation / warning dialogs under one sidebar item ("대화상자").
+// Alert Dialog is a modal Radix overlay (Portal) for a decision that must be confirmed or cancelled: no Close (X), no outside
+// dismiss. Action / Cancel are the HM Button: both confirmation and deletion use a Solid pair
+// (deletion pairs Cancel with a destructive Action).
+
+export function AlertDialogConfirmation({ defaultOpen }: { defaultOpen?: boolean }) {
+  return (
+    <AlertDialog defaultOpen={defaultOpen}>
+      <AlertDialogTrigger asChild>
+        <Button variant="primary" appearance="outline">
+          로그아웃
+        </Button>
+      </AlertDialogTrigger>
+      <AlertDialogContent>
+        <AlertDialogHeader>
+          <AlertDialogTitle>로그아웃하시겠습니까?</AlertDialogTitle>
+          <AlertDialogDescription>저장하지 않은 변경 사항은 사라집니다.</AlertDialogDescription>
+        </AlertDialogHeader>
+        <AlertDialogFooter>
+          <AlertDialogCancel appearance="solid">취소</AlertDialogCancel>
+          <AlertDialogAction variant="primary" appearance="solid">로그아웃</AlertDialogAction>
+        </AlertDialogFooter>
+      </AlertDialogContent>
+    </AlertDialog>
+  )
+}
+
+export function AlertDialogDestructive({ defaultOpen }: { defaultOpen?: boolean }) {
+  return (
+    <AlertDialog defaultOpen={defaultOpen}>
+      <AlertDialogTrigger asChild>
+        <Button variant="destructive" appearance="outline">
+          삭제
+        </Button>
+      </AlertDialogTrigger>
+      <AlertDialogContent>
+        <AlertDialogHeader>
+          <AlertDialogTitle>프로젝트를 삭제하시겠습니까?</AlertDialogTitle>
+          <AlertDialogDescription>삭제하면 되돌릴 수 없습니다. 프로젝트의 모든 데이터가 함께 삭제됩니다.</AlertDialogDescription>
+        </AlertDialogHeader>
+        <AlertDialogFooter>
+          <AlertDialogCancel appearance="solid">취소</AlertDialogCancel>
+          <AlertDialogAction variant="destructive" appearance="solid">
+            삭제
+          </AlertDialogAction>
+        </AlertDialogFooter>
+      </AlertDialogContent>
+    </AlertDialog>
+  )
+}