feat(storybook): add shared SW notice and refine SW previews

- Add StoryNotice and a withSWNotice decorator so every visible SW Story
  shows the common notice above its title; non-SW Stories are unaffected.
- Align the SW Header overview with the common SW Story page layout, let the
  preview Stage fill the available width and keep inner scroll on narrow screens.
- Rename SW/Footer to SW/하단 명령어바 (sidebar title only, Story IDs fixed via
  id: "sw-footer"), drop the top SWHeader from its preview and lower the
  workspace height bounds by the removed 49px.

src/components/story-page.css

@@ -61,3 +61,29 @@
   font-weight: var(--hm-input-font-weight);
 }
 .sb-page .sb-page-section-body { min-width: 0; }
+
+/* Notice above a page title (StoryNotice). Reuses .sb-page / .sb-page-inner (width and side margin are not redefined).
+   The frame drops its bottom gutter and pulls the next page up so the notice sits 24px above the title block's own top gutter. */
+.sb-page.sb-page-notice {
+  padding-bottom: 0;
+  margin-bottom: calc(24px - var(--sb-page-gutter));
+}
+.sb-page .sb-notice {
+  display: flex;
+  align-items: flex-start;
+  gap: 8px;
+  margin: 0;
+  font-size: var(--hm-label-font-size);
+  line-height: var(--hm-label-line-height);
+  font-weight: var(--hm-input-font-weight);
+  color: var(--hm-sem-fg-primary);
+  overflow-wrap: anywhere;
+}
+.sb-page .sb-notice-icon {
+  flex: none;
+  width: 20px;
+  height: 20px;
+  /* centers the icon on the first text line even when the line height differs from 20px */
+  margin-block: calc((var(--hm-label-line-height) - 20px) / 2);
+}
+.sb-page .sb-notice-text { min-width: 0; }