feat(ts): 实现 Polaris 可交互首页

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ts/web/nextjs/polaris/src/features/navigation/lib/sidebar-preference.ts

@@ -0,0 +1,10 @@
+export const SIDEBAR_STORAGE_KEY = "polaris.sidebar.collapsed"
+
+export function parseSidebarPreference(
+  value: string | null,
+  fallback: boolean,
+): boolean {
+  if (value === "true") return true
+  if (value === "false") return false
+  return fallback
+}