### System details

- Omarchy: 4.0.0-1
- Hardware: Apple iMac10,1
- CPU: Intel Core 2 Duo E7600 (Penryn, x86-64-v1)
- CPU features: SSE4.1; no SSE4.2, POPCNT, AVX, or AVX2
- Kernel: 7.1.8-arch1-3
- Package: voxtype-bin 0.7.5-1

### What's wrong?

Omarchy offers Dictation through `omarchy-voxtype-install` without checking
whether the CPU supports the installed Voxtype executable.

On this machine, `/usr/bin/voxtype` points directly to the AVX2 build:

```text
/usr/bin/voxtype -> /usr/lib/voxtype/voxtype-avx2
```

The CPU has no AVX or AVX2 support. The package contains AVX2 and AVX-512 CPU
executables, but no baseline executable:

```text
/usr/lib/voxtype/voxtype-avx2
/usr/lib/voxtype/voxtype-avx512
/usr/lib/voxtype/voxtype-onnx-avx2
/usr/lib/voxtype/voxtype-onnx-avx512
```

As a result, Omarchy allows Dictation to be installed on hardware that cannot
run its selected executable.

The installer currently proceeds directly to:

```bash
omarchy-pkg-add wtype voxtype-bin
voxtype setup --download --no-post-install
```

That attempts to execute the incompatible binary during installation.

### Steps to reproduce

1. Use Omarchy on an x86-64 CPU without AVX2.
2. Select `Install > AI > Dictation`.
3. Install Voxtype.
4. Inspect `/usr/bin/voxtype` or attempt to configure/use Dictation.
5. Observe that the command targets `voxtype-avx2`, which the CPU cannot run.

### Expected behavior

`omarchy-voxtype-install` should check for AVX2 before installing or executing
the CPU build.

If no compatible backend is available, the installer should stop before
downloading the package/model and display a clear explanation such as:

```text
Voxtype Dictation requires AVX2 on this hardware and cannot be installed.
```

If a compatible Vulkan or other backend can operate without AVX2, the installer
could select it before executing Voxtype. Otherwise, Dictation should remain
uninstalled.

A feature check such as looking for `avx2` in `/proc/cpuinfo` would be preferable
to checking CPU model names.

### Related issue

This is related to #7881, which reports Omarchy installing incompatible
Bun-based agents on older CPUs. Voxtype is a separate package and installation
path, but exposes the same missing CPU-capability gating.

### Diagnostic summary

`omarchy debug --no-sudo --print` reports:

```text
Intel Core2 Duo E7600
Architecture level: x86-64-v1
Flags: sse sse2 sse3 ssse3 sse4_1
```

No matching existing Omarchy issue was found when searching for Voxtype,
Dictation, AVX2, old CPUs, and illegal instructions.

Filed by GPT-5 via Codex.