Fix admin sidebar colors: use consistent dark sidebar instead of navbar colors for professional look

src/lib/theme-css.ts

@@ -57,9 +57,9 @@ export function themePaletteCss(selector: string, palette: ThemePalette): string
     `--color-overlay-text-readable:${semantic.byName.overlay};`,
     `--color-text-subtle-readable:${semantic.byName.subtle};`,
     `--color-text-disabled-readable:${semantic.byName.disabled};`,
-    `--admin-sidebar-background:${palette.color_navbar};`,
-    `--admin-sidebar-text-readable:${semantic.byName.sidebar};`,
-    `--admin-sidebar-muted-readable:color-mix(in srgb, ${semantic.byName.sidebar}, ${palette.color_navbar} 38%);`,
+    `--admin-sidebar-background:${admin.sidebar};`,
+    `--admin-sidebar-text-readable:${admin.sidebarText};`,
+    `--admin-sidebar-muted-readable:color-mix(in srgb, ${admin.sidebarText}, ${admin.sidebar} 38%);`,
     `--admin-input-text-readable:${semantic.byName.input};`,
     `--admin-canvas:${admin.canvas};`,
     `--admin-surface:${admin.surface};`,