feat: add Pyramid home dashboard

frontend/src/ai/workspace.ts

@@ -5,6 +5,7 @@ const contextLabels: Record<
   PageContext["page"],
   (context: PageContext) => string
 > = {
+  home: () => "上下文：首页看板",
   alphas: (context) =>
     `上下文：${context.alpha_id ? `Alpha ${context.alpha_id}` : "Alpha 列表"}${context.selected_ids?.length ? ` · 已选 ${context.selected_ids.length} 条` : ""}`,
   operators: () => "上下文：算子库",
@@ -30,9 +31,7 @@ export function pageFromHash(hash: string): WorkspacePage {
   const value = hash.replace(/^#/, "").split("?")[0];
   const page = value.startsWith("quantflow/") ? "quantflow" : value;
   if (page === "mcp-keys") return page;
-  return Object.hasOwn(contextLabels, page)
-    ? (page as WorkspacePage)
-    : "alphas";
+  return Object.hasOwn(contextLabels, page) ? (page as WorkspacePage) : "home";
 }
 
 type Destination = {