블록 에디터 빈 단락·슬래시·방향키·검색 폭 등 (v0.0.102)

- 빈 문단 마커 직렬화·공개 렌더 파싱
- 슬래시 메뉴 스크롤·하이라이트·블록 간 이동
- 헤더 검색 버튼 min-width, 네비 관리 안내 문구 정리

Co-authored-by: Cursor <cursoragent@cursor.com>

components/site/SiteHeader.vue

@@ -191,7 +191,7 @@ onBeforeUnmount(() => {
       <div class="site-header__search-slot flex min-w-0 justify-center justify-self-center px-1 sm:px-2">
         <button
         type="button"
-        class="site-header__search site-header__search--responsive hidden h-9 w-full max-w-[min(470px,100%)] cursor-pointer items-center rounded-lg px-3 text-left text-sm transition-colors hover:opacity-90 md:flex site-input"
+        class="site-header__search site-header__search--responsive hidden h-9 w-full min-w-[470px] max-w-[min(470px,100%)] cursor-pointer items-center rounded-lg px-3 text-left text-sm transition-colors hover:opacity-90 md:flex site-input"
         aria-label="검색 열기"
         @click="openSearchModal"
       >