style(storybook): refine manager sidebar, LNB inset and shared story frame

- Manager sidebar labels and sort order for the grouped pages; LNB 1-depth
  text start 12px (token, baseline and LNB doc updated)
- Shared story frame: drop the divider under section titles, side margin
  max 60px -> 30px; Foundation color/typography spacing
- Pseudo-state mirroring also pins :focus-visible via data-sb-focus while
  keeping the previous clones for compound rules (Slider Focus + Drag)

src/foundation/foundation.css

@@ -56,6 +56,10 @@
   .hm-foundation .hm-brand-color-row[data-palette] .hm-brand-color-chip:first-child .hm-foundation-swatch { border-radius: var(--hm-radius-control-md) 0 0 var(--hm-radius-control-md); }
   .hm-foundation .hm-brand-color-row[data-palette] .hm-brand-color-chip:last-child .hm-foundation-swatch { border-radius: 0 var(--hm-radius-control-md) var(--hm-radius-control-md) 0; }
 }
+/* 2026-11-13: Default stands apart from the Light / Dark steps with a 2px page-background seam on each side. The seam is an
+   outer shadow drawn over the neighbours, so chip widths, values and order do not change; at a line start it falls on the page. */
+.hm-foundation .hm-brand-color-row[data-palette] .hm-brand-color-chip[data-color-stage="default"] { position: relative; z-index: 1; }
+.hm-foundation .hm-brand-color-row[data-palette] .hm-brand-color-chip[data-color-stage="default"] .hm-foundation-swatch { box-shadow: -2px 0 0 var(--hm-sem-bg-content), 2px 0 0 var(--hm-sem-bg-content); }
 /* Name 14 Bold; role line 12 Regular (Default "기본색" 12 Medium); HEX 12. Dark text on a swatch reads thinner than white,
    so its role line and HEX use Medium. */
 .hm-foundation .hm-brand-color-row:is([data-palette], [data-company-id], [data-text-colors]) h3 { margin: 0; font-size: var(--hm-label-font-size); line-height: var(--hm-label-line-height); font-weight: var(--hm-font-weight-bold); color: inherit; }
@@ -84,7 +88,7 @@
 .hm-foundation .hm-brand-color-row:is([data-company-id], [data-text-colors]) .hm-foundation-swatch { border-radius: var(--hm-radius-control-md); }
 
 /* Typography: minimal type specimen page (presentation only, existing tokens; no card box, outer border or shadow).
-   Section titles, rhythm (title → 12px → divider → 16px → content, sections 28px apart) and the content indent (.sb-page-indent on
+   Section titles, rhythm (title → 12px → content, sections 28px apart) and the content indent (.sb-page-indent on
    Font Family, Font Weight and Specimens; Text Colors chips stay on the edge) come from the common Story page (story-page.css).
    Text levels: label / token 12/18/400 secondary, family and weight names 14/700 primary, specimen name and metrics 12/18 secondary;
    previews and samples carry the largest type. */
@@ -97,6 +101,8 @@
    the row is one column with the preview first. */
 .hm-foundation :is(.hm-typo-rows, .hm-typo-group) { container-type: inline-size; }
 .hm-foundation .hm-typo-row { display: grid; grid-template-columns: minmax(0, 1fr); gap: 8px 24px; align-items: center; }
+/* 2026-11-13: row content sits 12px inside on both sides; the row rules (border-top on the row) keep their start and width. */
+.hm-foundation .hm-typo-row { padding-inline: 12px; }
 .hm-foundation .hm-typo-row :is(p, code) { margin: 0; }
 .hm-foundation :is(.hm-typo-row-meta, .hm-typo-row-preview) { display: grid; gap: 2px; min-width: 0; }
 .hm-foundation .hm-typo-row-preview { order: -1; }
@@ -109,8 +115,7 @@
 .hm-foundation .hm-typo-kicker { color: var(--hm-sem-fg-secondary); }
 .hm-foundation .hm-typo-family-name { font-weight: var(--hm-font-weight-bold); }
 .hm-foundation .hm-typo-row .hm-typo-family-preview { margin-bottom: 4px; font-size: var(--hm-page-header-title-font-size); line-height: var(--hm-page-header-title-line-height); }
-/* Font Weight: one row per weight (name + value · token | preview), 12px above and below with a thin rule between rows only
-   (the section divider sits above the first row). */
+/* Font Weight: one row per weight (name + value · token | preview), 12px above and below with a thin rule between rows only. */
 .hm-foundation .hm-typo-weight { padding-block: 12px; }
 .hm-foundation .hm-typo-weight:first-child { padding-top: 0; }
 .hm-foundation .hm-typo-weight:last-child { padding-bottom: 0; }