## What happened

`omarchy plugin clone omarchy.bar` produces a bar that fails to load, and the
shell does not fall back to the built-in bar — so the result is **no bar at
all**: no layer surface, no exclusion zone.

This is on a pristine clone with no edits.

## Steps to reproduce

```bash
omarchy plugin clone omarchy.bar
omarchy restart shell

hyprctl layers    # no `omarchy-bar` namespace anywhere
hyprctl monitors  # reserved [0, 0, 0, 0]
```

Removing `"id": "swq.bar"` from the `bar` object in
`~/.config/omarchy/shell.json` and restarting the shell brings the bar back,
which confirms the clone is the trigger.

## Expected

Either the cloned bar loads, or the shell falls back to `omarchy.bar` as
`shell.qml` intends. Never zero bars.

## Cause

**1. A `Loader` cannot supply `required` properties.**

Plugin bars are loaded at `shell.qml:249` with:

```qml
Loader {
    id: pluginBarLoader
    source: shell.activeBarSourceUrl
    onLoaded: shell.configureBar(item, shell.activeBarManifest)
}
```

But `plugins/bar/Bar.qml` declares three required properties:

```qml
required property string omarchyPath
required property var barWidgetRegistry
required property var barConfig
```

A `Loader` using `source:` has no way to set those, so instantiation fails.
The default bar sidesteps this entirely by using `sourceComponent:`
(`defaultBarLoader`, `shell.qml:237`), where the bindings can be supplied.

The log shows:

```
WARN scene: file:///home/…/.config/omarchy/plugins/<id>.bar/Bar.qml[16:3]:
  Required property omarchyPath was not initialized
WARN scene: file:///home/…/.config/omarchy/plugins/<id>.bar/Bar.qml[18:3]:
  Required property barWidgetRegistry was not initialized
WARN scene: file:///home/…/.config/omarchy/plugins/<id>.bar/Bar.qml[23:3]:
  Required property barConfig was not initialized
```

**2. The fallback path throws before it can recover.**

`shell.qml:256` handles the load error with:

```qml
onStatusChanged: {
    if (status === Loader.Error) {
        var detail = errorString && errorString() ? errorString() : ""
        console.warn("bar option " + shell.activeBarId + " failed to load, …")
        shell.failedBarId = shell.activeBarId
    }
}
```

`errorString` is not a member of `Loader`, so this throws:

```
WARN scene: @shell.qml[256:-1]: ReferenceError: errorString is not defined
```

The exception aborts the handler before `shell.failedBarId` is assigned. Since
`activeBarId` (`shell.qml:180`) falls back only when
`selectedBarId !== failedBarId`, the fallback never engages — which is why the
failure is silent and total rather than degrading to the stock bar.

## Workaround

Changing the three properties to non-required in the clone makes it load
correctly:

```qml
property string omarchyPath: ""
property var barWidgetRegistry: null
property var barConfig: null
```

`configureBar()` assigns all three in `onLoaded` regardless, so nothing is lost.

Worth noting `plugins/bar/README.md` documents cloning as the supported way to
customize the bar, so this is on the intended path rather than an exotic setup.

The `errorString` bug is worth fixing independently of the first — a plugin bar
that fails for any other reason will also leave the user with no bar and no
clear indication why.

## System

| | |
|---|---|
| Omarchy | 4.0.1-1 |
| Hyprland | v0.56.2 |
| quickshell | 0.3.1-1 |
| CPU | AMD Ryzen AI MAX+ PRO 395 w/ Radeon 8060S |

Happy to attach `omarchy debug` output if useful.