## What happened

`omarchy setup security fingerprint` aborts with **"No fingerprint sensor detected."** on a laptop whose fingerprint reader works correctly through `fprintd` (enrolment and verification both succeed immediately before running the wizard).

## Expected

The wizard should detect the reader and configure PAM — or at least not refuse to continue on a reader that `fprintd` is already driving successfully.

## Root cause

`omarchy-hw-fingerprint` only scans `/sys/bus/usb/devices`:

```bash
usb_devices_path="${OMARCHY_USB_DEVICES_PATH:-/sys/bus/usb/devices}"

for dev in "$usb_devices_path"/*; do
  ...
done
```

That misses **SPI** readers entirely. This reader is a Goodix **GXFP51A7** on the SPI bus (`pxa2xx-spi`), ACPI HID `GXFP51A7`, exposed through `spidev`:

```
/sys/bus/spi/devices/spi-GXFP51A7:00   modalias: acpi:GXFP51A7:GXFP51A7:
```

It is a supported libfprint TOD reader (`libfprint-tod`), and both of these succeed before the wizard is run:

```
fprintd-enroll   # Enroll result: enroll-completed
fprintd-verify   # Verify result: verify-match (done)
```

## Secondary issue: package conflict

Even if detection returned true, the wizard runs:

```bash
sudo pacman -S --needed --noconfirm --ask 4 libfprint-git fprintd usbutils
```

`libfprint-git` provides `libfprint` and conflicts with the `libfprint-tod` package that TOD/SPI drivers load their `.so` from. On a machine that already has a working TOD driver, `--ask 4` would replace the working library, so proceeding can break a reader that currently works.

## Steps to reproduce

1. On a laptop with an SPI fingerprint reader supported by `libfprint-tod` (here: Huawei MateBook 13 2019, ACPI `GXFP51A7`), confirm the reader works:

   ```bash
   fprintd-enroll
   fprintd-verify
   ```

2. Run:

   ```bash
   omarchy setup security fingerprint
   ```

3. Observe:

   ```
   Setting up fingerprint scanner for authentication.

   No fingerprint sensor detected.
   ```

   Exits 1 before touching PAM.

## System details

- Omarchy: `4.0.4-1`
- Laptop: HUAWEI WRT-WX9 (MateBook 13 2019)
- CPU / GPU: Intel i7-8565U / UHD Graphics 620
- Kernel: `7.2.5-3-omarchy`
- Packages: `fprintd 1.94.5-2`, `libfprint-tod 1.95.2+tod1-1`
- Reader: `/sys/bus/spi/devices/spi-GXFP51A7:00` → `acpi:GXFP51A7:GXFP51A7:`
- `omarchy debug` is not a command in `4.0.4-1`, so diagnostics above are gathered directly.

## Suggested fix

1. Teach `omarchy-hw-fingerprint` to also consider SPI readers: scan `/sys/bus/spi/devices/*/modalias` for the known Goodix ACPI ids (e.g. `acpi:GXFP51*`, `acpi:GXFP5187*`), and only then consult the USB vendor/product list.
2. Make the dependency step aware of `libfprint-tod`: skip `libfprint-git` (or prompt) when a TOD driver is already installed and working, rather than replacing it.

## Workaround

Apply the PAM configuration the wizard installs after a successful enrol+verify by hand — `/etc/pam.d/sudo`, `/etc/pam.d/polkit-1` and `/etc/pam.d/omarchy-lock-fingerprint` — then the fingerprint works for `sudo`, polkit and the lock screen. This requires reading the wizard's source, so it is not discoverable for a normal user.