Title: Cloned menu gets null appLibrary — manifestHasKind Array.isArray fails on QVariantList kinds

## What happened
After cloning `omarchy.menu` to `cjmontero.menu` (only change: Spanish
"Desinstalar" strings), the Apps submenu is completely empty. The menu opens,
the `apps` provider entry exists, but `mergeAppRows()` aborts because the
scoped shell ships `appLibrary = null` for the clone. Stock (first-party)
menu works because it receives the global shell directly.

Shell log evidence (from temporary logging in the clone, since removed):
```
CJDEBUG mergeAppRows hasShell=true shellAppLib=false pluginId=cjmontero.menu manifestKinds=["menu","bar-widget"] items=334
CJDEBUG mergeAppRows ABORT no appLibrary
```
A standalone Quickshell probe on the same machine lists 52 desktop entries
(~35 visible after `launcher.hides` filtering), so the data is there — the
clone just never receives it.

## What was expected
A cloned menu (`clonedFrom: omarchy.menu`, kinds `["menu","bar-widget"]`,
enabled, stock disabled) receives a working `appLibrary` like the stock menu,
so Apps lists installed applications.

## Steps to reproduce
1. `omarchy plugin clone omarchy.menu` (or equivalent clone to `<user>.menu`)
2. Confirm bar uses the clone and stock `omarchy.menu` is disabled
3. `omarchy-shell shell summon omarchy.menu '{"menu":"apps"}'` (or open Apps from the menu)
4. Apps submenu is empty; shell log shows `appLibrary` null in `mergeAppRows()`

## Root cause
`shell.qml` `manifestHasKind()` uses `Array.isArray(manifest.kinds)`.
A manifest that reaches the panel path through the Instantiator as `modelData`
carries `kinds` as a `QVariantList`, and `Array.isArray()` is false for those
even though they index like an array — so the check fails, the scoped shell
is built with `appLibrary: null`, and the result is cached.

## Proposed patch (`shell.qml`)
Duck-type instead of `Array.isArray`, so it holds for both plain JS arrays
and `QVariantList`:
```qml
function manifestHasKind(manifest, kind) {
  // A manifest that reached us through a model — the panel Instantiator hands
  // out modelData — carries kinds as a QVariantList, and Array.isArray() is
  // false for those even though they index like an array.
  var kinds = manifest ? manifest.kinds : null
  return !!kinds && typeof kinds.indexOf === "function"
    && kinds.indexOf(kind) !== -1
}
```
Reported as verified by the reporter: with the patch the same shell logs
rows in `mergeAppRows()` and the Apps submenu renders normally.
Note: the other three `Array.isArray(m.kinds)` sites (`isBarOptionManifest`,
`computePanelEntries`, `_syncServices`) only ever see raw registry manifests,
never `modelData`, so they are not affected — though aligning them would be
consistent.

## System details
- Omarchy: 4.0.4-1 (`omarchy version`)
- Base: Arch Linux rolling, Hyprland (Wayland), `XDG_CURRENT_DESKTOP=Hyprland`
- CPU: Intel(R) Core(TM) i5-6500TE CPU @ 2.30GHz
- GPU: Intel Corporation Skylake-S GT2 [HD Graphics 530] (rev 06)
- Note: `omarchy debug` does not exist in 4.0.4-1
  (`Unknown Omarchy command`), so no debug-log URL; diagnostics above are
  from the shell journal (`journalctl --user -t omarchy-shell`) and a
  Quickshell `DesktopEntries` probe.

## Local workaround (kept out of this report's scope)
Menu-side fallback inside the clone (`cjmontero.menu/Menu.qml` only):
list `DesktopEntries` directly with the same hide rules when
`root.appLibrary` is null. Works, but the one-line upstream fix above is
the correct resolution.