feat(foundation): add company colors story

Add Foundation > Company Colors as a separate Storybook menu placed right
after Color. It shows the 7 affiliates and 14 colors from the existing
companyColorPresets (main first, then secondary) with the Color chip styles
and the Default emphasis reused for the main color. Theme tokens, public API
and the existing Color story are unchanged.

- Foundation sort order: Color, Company Colors, Typography, Layout
- Company chip width rule scoped to the company rows
- Document the menu in brand-color-steps.md
- Add the new story to the Story Inventory records

src/foundation/foundation.css

@@ -38,3 +38,6 @@
 /* New common background stop IDs stay on one line at the supported widths. */
 .hm-foundation .hm-color-gradient-stops .hm-brand-color-chip[data-gradient-stop-token] { flex-basis: 220px; }
 .hm-foundation .hm-color-foreground-sample { padding: 16px; background: var(--hm-sem-bg-surface); }
+
+/* Company Colors: keep each chip close to the Color row width so 1-3 chips per company do not stretch across the page. */
+.hm-foundation .hm-brand-color-row[data-company-id] .hm-brand-color-chip { flex: 0 1 140px; }