fix: load uinput in Arch hook

[FromSi]

What happened

On my Manjaro KDE Wayland system, Logitune detected the mouse and received
button events correctly, but remapped button actions did nothing.

The log showed that hidraw access was working:

button event: CID c4 pressed
button 6 action type= 7 payload= "Next"

But uinput initialization failed:

UinputInjector: uinput init failed (no /dev/uinput access?)
Keystrokes will not be injected.

Root cause

In my case, /dev/uinput existed, but the actual uinput kernel device was
not loaded or registered:

/dev/uinput existed as crw------- root root
/sys/class/misc/uinput did not exist
/proc/misc did not contain uinput
lsmod did not show uinput
udevadm info -n /dev/uinput returned "Unknown device"

Because of that, reloading and triggering udev rules was not enough. The rule
with TAG+="uaccess" had no live misc/uinput device to apply to.

Fix

This patch loads the uinput kernel module in the Arch install hook before
reloading and triggering udev rules.

It then triggers:

• misc/uinput, so uaccess can be applied to /dev/uinput
• hidraw, so Logitech device permissions are refreshed as before

After manually running modprobe uinput and reloading udev rules on my system,
Logitune stopped failing uinput init, and button remaps started working.

[mmaher88]

Verified: brings the Arch hook in line with the deb postinst and RPM spec, which already narrow udevadm trigger to hidraw/misc instead of re-triggering every device. The modprobe uinput is the right call — without the module loaded there's no /dev/uinput node for udev to tag with uaccess. The || true guards also mean a failing hook can't abort the install. Thanks!