### Description

When a third-party clone of a menu plugin is loaded (e.g., `omarchy.menu` cloned to `ankardo.menu` with `kinds: ["menu", "bar-widget"]`), the Omarchy shell incorrectly revokes its `PluginShellApi` shortly after instantiation, causing injected properties like `root.shell` to become `null`. This breaks access to `appLibrary` and completely empties the app list.

### Root Cause

The bug is located in `shell.qml` in the `manifestHasKind` function:

```javascript
  function manifestHasKind(manifest, kind) {
    return !!manifest && Array.isArray(manifest.kinds)
      && manifest.kinds.indexOf(kind) !== -1
  }
```

When `manifest` is read from an `Instantiator`'s `modelData` (as is the case with `panelEntry.manifest` passed to `pluginShellFor`), the Qt/QML engine wraps the underlying JS Array inside a `QJSValue` or `QVariant`. Consequently, `Array.isArray(manifest.kinds)` incorrectly returns `false`.

This false evaluation cascades into `pluginShellCapabilityProfile`, calculating an unexpected profile (e.g. `own-service|no-bar|no-indicators|no-menu`), which mismatches the original profile descriptor. The mismatch triggers `shell.revokePluginShellApi(shellKey)`, destroying the C++ API wrapper.

### Proposed Fix

Avoid using strict `Array.isArray()` on objects originating from QML models. Duck-typing such as checking `manifest.kinds.length > 0` works correctly across QJSValue boundaries:

```javascript
  function manifestHasKind(manifest, kind) {
    return !!manifest && manifest.kinds && manifest.kinds.length > 0
      && manifest.kinds.indexOf(kind) !== -1
  }
```

### Steps to Reproduce
1. Clone `omarchy.menu` using `omarchy menu plugin clone omarchy.menu`
2. Set the newly cloned plugin active on the bar.
3. Open the menu. Observe that the app list is entirely empty because `appLibrary` cannot be accessed (since `root.shell` was set to `null`).

### System Info
- Omarchy version: 4.0.3-1