message: Update: Display page info on appbar.
diff: @@ -277,7 +277,20 @@ const Header: React.FC<Props> = ({
  </div>
  </Popover>
  {/* Page Popover */}
  - <Popover {...pagePopover.bind}>TODO</Popover>
  + <Popover {...pagePopover.bind}>
  + <div className="flex flex-col gap-1 text-on-surface">
  + {page.group && (
  + <div className="text-xxs text-on-surface-low">{page.group}</div>
  + )}
  + <div className="text-xxs">{page.id}</div>
  + <div className="text-base text-on-surface-high font-bold">
  + {page.title}
  + </div>
  + {page.description && (
  + <CommonMark on={ON.SURFACE} data={page.description} />
  + )}
  + </div>
  + </Popover>
  {/* Contents Popover */}
  <Popover {...contentsPopover.bind}>
  {page.contents.map(function (content) {
  @@ -287,7 +300,7 @@ const Header: React.FC<Props> = ({
  on={ON.SURFACE}
  size={BUTTON_SIZE.SM}
  variant={BUTTON_VARIANT.TEXT}
  - label={content.title}
  + label={content.title || content.id}
  data={content}
  onClick={handleContentClick}
  />
  