feat(web): regroup console nav into 7 groups, split downloads/plans/tasks, add legacy redirects

- Sidebar: 概览/资源/订阅/下载/整理/Agent/系统, 18 items (+ 定时任务); single
  active item via findNavItem; 待处理 badge; collapsed rail groups; mobile drawer
  shares NAV_GROUPS.
- New pages: /downloads (queue + cache watermark header), /downloads/plans,
  /downloads/:id, /tasks (business tasks only) + /tasks/:id detail, /rules.
- Legacy links: ?tab= on tasks/subscriptions/sources redirect via clientLoader;
  /tasks/:downloadId falls back to /downloads/:id.
- List filters in URL query; settingsPath() helper for settings deep links.
- Copy per glossary (待处理, 收录策略, 引擎面板, 文件管理, 版本目标).

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

apps/web/app/api/tasks.ts

@@ -266,7 +266,7 @@ export function buildTimeline(input: {
       detail:
         [t.attempts > 1 ? `第 ${t.attempts} 次尝试` : null, t.waitReason, err].filter(Boolean).join(" · ") || null,
       tone: TASK_STATUS_TONE[t.status],
-      ...(t.engineRunId ? { href: `/console/engine/${encodeURIComponent(t.engineRunId)}` } : {}),
+      href: `/console/tasks/${encodeURIComponent(t.id)}`,
       ongoing: ACTIVE_TASK.includes(t.status),
     });
   }