style(admin): unify text color hierarchy with foundation gray

packages/ui/src/theme/primitives.css

@@ -58,3 +58,12 @@
   --hm-orange-dark-2: #883700;
   --hm-orange-dark-3: #4f2000;
 }
+
+/* Foundation Gray text steps (2026-11-11). Admin text hierarchy only; SW keeps its own tokens. */
+:root {
+  --hm-gray-900: #212121;
+  --hm-gray-800: #424242;
+  --hm-gray-700: #616161;
+  --hm-gray-600: #757575;
+  --hm-gray-500: #9e9e9e;
+}