Show New Workspace isolation controls immediately (#2702)

* fix(workspaces): show isolation without checkout delay

* fix(workspaces): trust hydrated project capability

* fix(workspaces): resolve branch before creation

* fix(workspaces): honor invalidated checkout status

* fix(workspaces): preserve isolation while projects load

* fix(workspaces): keep provisional project routes usable

Route-derived projects do not know their worktree capability. Represent that uncertainty at the placement boundary so remembered worktree intent survives hydration without disabling the New Workspace screen indefinitely.

packages/app/src/screens/new-workspace-picker-item.ts

@@ -1,5 +1,6 @@
 import type { CreatePaseoWorktreeInput } from "@getpaseo/client/internal/daemon-client";
 import type { ForgeSearchItem } from "@getpaseo/protocol/messages";
+import type { CheckoutStatusPayload } from "@/git/checkout-status-cache";
 
 export type PickerItem =
   | { kind: "branch"; name: string }
@@ -43,3 +44,16 @@ export function pickerItemToCheckoutRequest(
     }
   }
 }
+
+export function resolveCheckoutRequest(
+  selectedItem: PickerItem | null,
+  checkoutStatus: CheckoutStatusPayload,
+): PickerCheckoutRequest | undefined {
+  const selectedCheckoutRequest = pickerItemToCheckoutRequest(selectedItem);
+  if (selectedCheckoutRequest) return selectedCheckoutRequest;
+  if (!checkoutStatus.currentBranch) return undefined;
+  return {
+    action: "branch-off",
+    refName: checkoutStatus.currentBranch,
+  };
+}