GUI should provide better feedback when unable to authenticate

**Describe the bug**

Cannot launch a multipass VM or start the GUI on OSX

**To Reproduce**

1. `brew install multipass`
2. `multipass launch`
launch failed: The client is not authenticated with the Multipass service.
Please use 'multipass authenticate' before proceeding.
3. `multipass authenticate`
Please enter passphrase:
authenticate failed: Passphrase is not set. Please `multipass set local.passphrase` with a trusted client.
4. `multipass set local.passphrase`
Please enter passphrase:
Please re-enter passphrase:
set failed: The client is not authenticated with the Multipass service.
Please use 'multipass authenticate' before proceeding.
5. `multipass authenticate`
Stuck in that loop

The UI shows: `Waiting for daemon...`

(Note that I had a very early version of multipass installed, removed it as some point and recently reinstalled 1.15.1)

**Expected behavior**

Some error message explaining what is wrong.

**Logs**

```
[2025-06-06T08:38:54.966] [warning] [Qt] QNetworkDiskCache::prepare() unable to open temporary file
[2025-06-06T08:38:54.966] [debug] [update] Latest Multipass release available is version 1.15.1
[2025-06-06T08:38:54.968] [debug] [blueprint provider] Loading "anbox-cloud-appliance" v1
[2025-06-06T08:38:54.969] [debug] [blueprint provider] Loading "charm-dev" v1
[2025-06-06T08:38:54.970] [debug] [blueprint provider] Loading "docker" v1
[2025-06-06T08:38:54.970] [debug] [blueprint provider] Loading "jellyfin" v1
[2025-06-06T08:38:54.971] [debug] [blueprint provider] Loading "minikube" v1
[2025-06-06T08:38:54.971] [debug] [blueprint provider] Loading "ros2-humble" v1
[2025-06-06T08:38:54.971] [debug] [blueprint provider] Loading "ros2-jazzy" v1
[2025-06-06T08:38:54.978] [info] [rpc] gRPC listening on unix:/var/run/multipass_socket
[2025-06-06T08:38:54.978] [debug] [async task] fetch manifest periodically
[2025-06-06T08:38:54.983] [info] [VMImageHost] Did not find any supported products in "appliance"
[2025-06-06T08:38:54.987] [debug] [qemu-img] [5152] started: qemu-img snapshot -l /var/root/Library/Application Support/multipassd/qemu/vault/instances/lts/ubuntu-22.04-server-cloudimg-arm64.img
[2025-06-06T08:38:55.683] [debug] [qemu-img] [5156] started: qemu-img amend -o compat=1.1 /var/root/Library/Application Support/multipassd/qemu/vault/instances/lts/ubuntu-22.04-server-cloudimg-arm64.img
[2025-06-06T08:38:55.694] [info] [sshfs-mount-handler] initializing mount /Users/work => Home in 'lts'
[2025-06-06T08:38:55.696] [info] [daemon] Starting Multipass 1.15.1+mac
[2025-06-06T08:38:55.697] [info] [daemon] Daemon arguments: /Library/Application Support/com.canonical.multipass/bin/multipassd --verbosity debug
[nothing newer]
```

**Additional info**
- OS: macOS 15.5 (24F74)
- CPU architecture or model: Apple M2 Pro
- `multipass 1.15.1+mac`
- `info failed: The client is not authenticated with the Multipass service. Please use 'multipass authenticate' before proceeding.`
- `multipass get local.driver` --> same

Reproduce the loop with the listed multipass launch, authenticate, and set commands, then trace why the GUI remains at “Waiting for daemon...” when authentication fails. Done means the GUI presents an actionable error explaining the authentication problem instead of waiting indefinitely.

Written by the indexing model from the issue text.