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

scripts/theme-templates/default.css

@@ -8,10 +8,11 @@
   --hm-color-surface-default: var(--hm-sem-palette-white);
   --hm-color-surface-content: var(--hm-sem-palette-beige-light);
   --hm-color-surface-subtle: var(--hm-sem-palette-warm-neutral-muted);
-  --hm-color-text-primary: var(--hm-sem-palette-green-dark-1);
-  --hm-color-text-secondary: var(--hm-sem-palette-warm-neutral-dark);
+  /* Admin text hierarchy (2026-11-11): Primary Gray 900, Secondary Gray 700, Placeholder Gray 600. Brand primitives keep their values. */
+  --hm-color-text-primary: var(--hm-sem-palette-gray-900);
+  --hm-color-text-secondary: var(--hm-sem-palette-gray-700);
   --hm-color-text-inverse: var(--hm-sem-palette-white);
-  --hm-color-text-placeholder: var(--hm-sem-palette-neutral-gray-500);
+  --hm-color-text-placeholder: var(--hm-sem-palette-gray-600);
   --hm-color-border-default: var(--hm-sem-palette-warm-neutral-mid);
   --hm-color-border-control: var(--hm-sem-palette-warm-neutral-pale);
   /* Common Focus color. Trial value: Light 2 (#266651), pending user confirmation. Was --hm-color-primary. */
@@ -236,3 +237,12 @@
   --hm-sem-palette-orange-dark-2: {{color.palette.orange-dark-2|var(--hm-orange-dark-2)}};
   --hm-sem-palette-orange-dark-3: {{color.palette.orange-dark-3|var(--hm-orange-dark-3)}};
 }
+
+/* Foundation Gray text steps; only the text aliases above reference them. */
+:root, [data-hm-theme] {
+  --hm-sem-palette-gray-900: {{color.palette.gray-900|var(--hm-gray-900)}};
+  --hm-sem-palette-gray-800: {{color.palette.gray-800|var(--hm-gray-800)}};
+  --hm-sem-palette-gray-700: {{color.palette.gray-700|var(--hm-gray-700)}};
+  --hm-sem-palette-gray-600: {{color.palette.gray-600|var(--hm-gray-600)}};
+  --hm-sem-palette-gray-500: {{color.palette.gray-500|var(--hm-gray-500)}};
+}