omarchy webcam picker offers unusable IPU6 raw Bayer node alongside real capture device

[oren]

Summary

On Intel IPU6 laptops (most 11th-gen+ Intel hardware), omarchy-menu's
"With desktop + microphone audio + webcam" flow opens a webcam picker
that lists the IPU6's raw Bayer-only /dev/video0 alongside the actual
capture device (typically a v4l2loopback node fed by v4l2-relayd +
icamerasrc). Picking /dev/video0 produces a black overlay or
STREAMON: Link severed because that node only advertises raw sensor
formats. Users have to know which entry is the real camera.

Reproduction

On an IPU6/IPU7 laptop with the Intel camera HAL stack installed
(intel-ipu6-camera-bin, intel-ipu6ep-camera-hal-git, icamerasrc-git,
v4l2loopback-dkms, v4l2-relayd), v4l2-ctl --list-devices returns
two camera groups:

ipu6 (PCI:0000:00:05.0):
        /dev/video0
        /dev/video1
        ...
        /dev/video31
        /dev/media0

Built-in Camera (platform:v4l2loopback-042):
        /dev/video42

get_webcam_list collapses each group to its first device, so the
picker shows two entries:

/dev/video0   ipu6 (PCI:0000:00:05.0)
/dev/video42  Built-in Camera (platform:v4l2loopback-042)

Picking /dev/video0 opens ffplay against an output-only / raw-Bayer
node and yields a black overlay; only /dev/video42 works.

Related: omarchy-capture-screenrecording auto-detect

The auto-detect path in omarchy-capture-screenrecording's
start_webcam_overlay (around line 54) is also affected, and arguably
worse - it does:

WEBCAM_DEVICE=$(v4l2-ctl --list-devices 2>/dev/null \
  | grep -m1 "^[[:space:]]*/dev/video" | tr -d '\t')

which always picks /dev/video0 on this hardware (the first
indented /dev/video* line in the output). So --with-webcam without
--webcam-device always lands on the broken IPU6 raw node. The user
gets a black overlay with no error.

Suggested fix

Filter both paths to entries whose Device Caps include Video Capture.
Either parse v4l2-ctl --device=$dev --info, or check the udev
ID_V4L_CAPABILITIES property - IPU6 ISP nodes report Video Output /
I/O MC only, while the v4l2loopback node reports Video Capture.

On a clean IPU6 + loopback setup this collapses the picker list to a
single entry (/dev/video42) and the existing count == 1 auto-pick
path takes over. On a UVC-only laptop (current behavior), the single
/dev/video0 entry still passes the filter. No UX changes for non-IPU6
users.

Environment

• Omarchy 3.8.0
• Intel Core i7-1370P (Raptor Lake-P, IPU6EP)
• Driver/HAL: intel-ipu6-dkms-git, intel-ipu6-camera-bin, intel-ipu6ep-camera-hal-git, icamerasrc-git
• Camera surfaced via v4l2-relayd to /dev/video42 (v4l2loopback)