fix(input): resolve the real evdev node for input-linux, not the sysfs name

UI_GET_SYSNAME returns the input-class directory name (inputNNN), not a usable
device node -- /dev/input/inputNNN does not exist, so QEMU's input-linux failed
with "Could not open". Resolve the actual evdev node (/dev/input/eventN) as the
event* child of /sys/class/input/<sysname>/. Confirmed against the live host
sysfs. The unit path can't exercise this (no /dev/uinput in CI) -- armed only.

Bump 0.3.10.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.16)
 # Single source of truth for the version: CI passes -DVMSIG_VERSION=${TAG#v}, so the project
 # version (-> libvgpu-perception SONAME/.so version) and the .deb version come from one tag.
-set(VMSIG_VERSION "0.3.9" CACHE STRING "Release version (MAJOR.MINOR.PATCH); CI passes the tag")
+set(VMSIG_VERSION "0.3.10" CACHE STRING "Release version (MAJOR.MINOR.PATCH); CI passes the tag")
 project(vmsig VERSION ${VMSIG_VERSION} LANGUAGES C)
 
 set(CMAKE_C_STANDARD 17)

src/si/input/linux/uinput_driver.c

@@ -31,6 +31,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <dirent.h>
 #include <sys/ioctl.h>
 #include <linux/uinput.h>
 #include <linux/input-event-codes.h>
@@ -120,8 +121,28 @@ static int uinput_create(const uinput_role* role, const vmctl_uinput_id* id,
 
     char sysname[64] = {0};
     evdev[0] = '\0';
-    if (ioctl(fd, UI_GET_SYSNAME(sizeof sysname), sysname) >= 0)
+    /* UI_GET_SYSNAME returns the input-class directory name (e.g. "input174"), NOT the usable
-        snprintf(evdev, 64, "/dev/input/%s", sysname);
+     * device node: a bare /dev/input/<sysname> does not exist (QEMU input-linux fails to open
+     * it). The evdev character device is /dev/input/eventN, exposed as the "event*" child of
+     * /sys/class/input/<sysname>/ — resolve it there. */
+    if (ioctl(fd, UI_GET_SYSNAME(sizeof sysname), sysname) >= 0) {
+        char dpath[128];
+        snprintf(dpath, sizeof dpath, "/sys/class/input/%s", sysname);
+        DIR* dir = opendir(dpath);
+        if (dir) {
+            struct dirent* de;
+            while ((de = readdir(dir)) != NULL)
+                if (strncmp(de->d_name, "event", 5) == 0) {
+                    size_t nl = strlen(de->d_name);
+                    if (nl + 11 < 64) {            /* "/dev/input/" is 11 chars + name + NUL */
+                        memcpy(evdev, "/dev/input/", 11);
+                        memcpy(evdev + 11, de->d_name, nl + 1);
+                    }
+                    break;
+                }
+            closedir(dir);
+        }
+    }
 
     if (!evdev[0]) {
         ioctl(fd, UI_DEV_DESTROY);