OSS macOS startup crashes while constructing cloud-only menu actions

[BunsDev]

Problem

Launching the OSS channel on macOS can abort during menu construction because hosted-only actions have no registered bindings when cloud services are unavailable. The observed failure is action should have a name: ReferAFriend; exposing the next unavailable action also reaches ToggleWarpDrive.

Reproduction

1. Build and launch the macOS app with Channel::Oss.
2. Let the root view construct the native menu bar.
3. Observe the process abort before a usable first frame.

Expected behavior

The OSS app starts normally and omits the Drive menu, referral action, Drive toggle, and shared-blocks action.

Acceptance criteria

• Hosted-only menu entries are not constructed when cloud services are unavailable.
• A macOS OSS startup integration test verifies that the root view initializes.
• Focused public-surface tests pin each cloud-only menu gate.

PR #225 implements and verifies this fix.