feat(ui): fold the Workflows page into Dashboard → Analytics → Workflow

The workflow analytics now render under the Analytics tab's Workflow
sub-tab; ?tab= and ?sub= deep-link the Dashboard, /workflows redirects there,
and the sidebar drops its Workflows item.

client/src/components/DocumentTitle.tsx

@@ -24,8 +24,6 @@ export function DocumentTitle() {
     title = `${t("sessions")} · ${sessionId.slice(0, 8)}`;
   } else if (path.startsWith("/sessions")) {
     title = t("sessions");
-  } else if (path.startsWith("/workflows")) {
-    title = t("workflows");
   } else if (path.startsWith("/workspace")) {
     title = t("workspace");
   } else if (path.startsWith("/settings")) {