Keep composer autocomplete visible after route hops (#1851)

* fix(app): keep composer autocomplete visible after route hops

Workspace callers now express only the target workspace. The navigation helper chooses whether to pop to a mounted host route or fall back, and active-workspace tracking ignores stale hidden route params while app-wide routes are foregrounded.

* test(app): address workspace navigation review

* fix(app): parse decoded legacy workspace routes

* fix(app): ignore decoded legacy tab routes

* test(app): use canonical offline workspace route

packages/app/e2e/workspace-navigation-regression.spec.ts

@@ -256,9 +256,7 @@ test.describe("Workspace navigation regression", () => {
       await ws.close({ code: 1008, reason: "Blocked cold offline workspace route test." });
     });
 
-    await page.goto(
-      `/h/${encodeURIComponent(serverId)}/workspace/${encodeURIComponent("/tmp/paseo-missing-workspace")}`,
-    );
+    await page.goto(buildHostWorkspaceRoute(serverId, "/tmp/paseo-missing-workspace"));
 
     await expectHostConnectingOrOffline(page);
     await expectMenuButtonVisible(page);