Fix cold workspace URL sidebar navigation

Directly opening a workspace URL created a different React Navigation state shape than entering from /. Expo Router parsed the URL as a workspace layout route with a nested index child whose route.path and params pointed at the original workspace. Later sidebar navigation used router.dismissTo for another workspace. React Navigation's POP_TO reused the existing workspace route by name and updated the parent params, but preserved the nested child state. The result was a hybrid state: parent workspace params for B, child index path for A. Expo Router serialized the focused child path, so the address bar stayed on A and sidebar clicks looked like no-ops.

The fix is to stop using workspace/[workspaceId]/_layout.tsx as the actual screen. That layout did not render a Slot, so it only added an extra navigation level for Expo Router to preserve. Move the workspace UI, bootstrap boundary, open-intent consumption, and retained WorkspaceDeck into the leaf index route, making /h/:serverId/workspace/:workspaceId one real rendered route.

Keep workspace switches on navigateToWorkspace/router.dismissTo. This is not another replace workaround: replace previously created duplicate mounted workspace shells. The route-shape fix removes the stale nested child state that made dismissTo fail after cold deep links.

Also route archive/new-agent and notification flows through the centralized workspace navigation path so they do not bypass the same route contract.

Regression coverage: cold-load workspace A, click workspace B in the sidebar, and assert the URL changes to B. Verified with workspace-navigation-regression.spec.ts, settings-navigation.spec.ts, npm run typecheck, and npm run lint.

packages/app/src/utils/new-agent-routing.test.ts

@@ -2,25 +2,11 @@ import { describe, expect, it } from "vitest";
 
 import type { CheckoutStatusPayload } from "@/hooks/use-checkout-status-query";
 import {
-  buildNewAgentRoute,
   parseAgentKey,
   resolveNewAgentWorkingDir,
   resolveSelectedAgentForNewAgent,
 } from "./new-agent-routing";
 
-describe("buildNewAgentRoute", () => {
-  it("falls back to server workspace route with dot workspace when no working directory is provided", () => {
-    expect(buildNewAgentRoute("srv-1", undefined)).toBe("/h/srv-1/workspace/.");
-    expect(buildNewAgentRoute("srv-1", "   ")).toBe("/h/srv-1/workspace/.");
-  });
-
-  it("encodes the working directory as a workspace path segment", () => {
-    expect(buildNewAgentRoute("srv-1", "/Users/me/dev/paseo")).toBe(
-      "/h/srv-1/workspace/b64_L1VzZXJzL21lL2Rldi9wYXNlbw",
-    );
-  });
-});
-
 describe("resolveNewAgentWorkingDir", () => {
   it("returns the current cwd for regular checkouts", () => {
     expect(resolveNewAgentWorkingDir("/repo/path", null)).toBe("/repo/path");

packages/app/src/utils/new-agent-routing.ts

@@ -1,7 +1,6 @@
 import type { CheckoutStatusPayload } from "@/hooks/use-checkout-status-query";
 import {
   parseHostWorkspaceOpenIntentFromPathname,
-  buildHostWorkspaceRoute,
   parseHostAgentRouteFromPathname,
   parseHostWorkspaceRouteFromPathname,
 } from "@/utils/host-routes";
@@ -68,8 +67,3 @@ export function resolveNewAgentWorkingDir(
 
   return inferMainRepoRootFromPaseoWorktreePath(cwd) ?? cwd;
 }
-
-export function buildNewAgentRoute(serverId: string, workingDir?: string | null) {
-  const trimmedWorkingDir = workingDir?.trim();
-  return buildHostWorkspaceRoute(serverId, trimmedWorkingDir || ".");
-}

packages/app/src/utils/notification-routing.test.ts

@@ -45,14 +45,14 @@ describe("resolveNotificationTarget", () => {
 });
 
 describe("buildNotificationRoute", () => {
-  it("routes to workspace with one-shot open intent when workspace id is present", () => {
+  it("routes to the agent path when workspace id is present", () => {
     expect(
       buildNotificationRoute({
         serverId: "srv-1",
         agentId: "agent-1",
         workspaceId: "ws-main",
       }),
-    ).toBe("/h/srv-1/workspace/ws-main?open=agent%3Aagent-1");
+    ).toBe("/h/srv-1/agent/agent-1");
   });
 
   it("routes directly to server-scoped agent path when both ids are present", () => {

packages/app/src/utils/notification-routing.ts

@@ -1,9 +1,5 @@
 import type { Href } from "expo-router";
-import {
-  buildHostAgentDetailRoute,
-  buildHostRootRoute,
-  buildHostWorkspaceRoute,
-} from "@/utils/host-routes";
+import { buildHostAgentDetailRoute, buildHostRootRoute } from "@/utils/host-routes";
 
 type NotificationData = Record<string, unknown> | null | undefined;
 type NotificationRoute = Extract<Href, string>;
@@ -30,12 +26,8 @@ export function resolveNotificationTarget(data: NotificationData): {
 }
 
 export function buildNotificationRoute(data: NotificationData): NotificationRoute {
-  const { serverId, agentId, workspaceId } = resolveNotificationTarget(data);
+  const { serverId, agentId } = resolveNotificationTarget(data);
   if (serverId && agentId) {
-    if (workspaceId) {
-      const base = buildHostWorkspaceRoute(serverId, workspaceId);
-      return `${base}?open=${encodeURIComponent(`agent:${agentId}`)}` as const;
-    }
     return buildHostAgentDetailRoute(serverId, agentId);
   }
   if (serverId) {