feat(web): IA-3 navigation, legacy redirects and top-bar inbox (FE-1)

Sidebar becomes 5 groups (overview / resources / subscriptions / organize /
system). Pending items move to a top-bar inbox with badge and grouped
dropdown. Engine panel, schedules and identity pages redirect to the task
page, its plan tab and media overview views; the download plan becomes a
second tab of the download panel. nav.test and smoke cover the new routes.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/routes/console/downloads.plans.tsx

@@ -12,13 +12,14 @@ import { consolePath } from "~/components/console/nav.ts";
 import { PageHeader } from "~/components/console/page-header.tsx";
 import { StatusBadge } from "~/components/console/status-badge.tsx";
 import { useQueryState } from "~/components/console/use-query-state.ts";
+import { DownloadsTabs } from "~/components/downloads/downloads-tabs.tsx";
 import { PRIORITY } from "~/components/library/labels.ts";
 import { Button } from "~/components/ui/button.tsx";
 import { relTime } from "~/components/workbench/release-fields.ts";
 import { planReasonText } from "~/lib/labels.ts";
 import { formatBytes, formatDateTime } from "~/lib/utils.ts";
 
-export const meta = () => [{ title: "下载计划 · UHD 媒体自动化控制台" }];
+export const meta = () => [{ title: "下载计划 · 下载面板 · UHD 媒体自动化控制台" }];
 
 const PURPOSE = { fill: "补缺", upgrade: "升级", replace_source: "换源" } as const;
 
@@ -77,7 +78,8 @@ export default function DownloadPlansPage() {
 
   return (
     <>
-      <PageHeader title="下载计划" description="候选被选中后生成计划,同时预留版本目标、空间与预算。" />
+      <PageHeader title="下载面板" description="候选被选中后生成计划,同时预留版本目标、空间与预算。" />
+      <DownloadsTabs />
       <FilterBar onReset={f.active ? f.reset : undefined}>
         <FilterSelect
           label="状态"