docs(evdev): add uinput-access.md

Author: haithium

docs/src/evdev/tutorials/uinput-access.md

@@ -0,0 +1,73 @@
+---
+order: 7
+title: UInput Access Setup
+description:
+  Configure permissions so Lua programs can create virtual input devices with
+  uinput.
+---
+
+# UInput Access Setup
+
+Creating virtual input devices requires `/dev/uinput` to exist and be writable
+by the current user.
+
+## Group setup
+
+1. Create a `uinput` group:
+
+   ```bash
+   sudo groupadd --system uinput
+   ```
+
+1. Add your user to it:
+
+   ```bash
+   sudo usermod -aG uinput "$USER"
+   ```
+
+## Udev setup
+
+1. Create a udev rule:
+
+   ```bash
+   echo 'KERNEL=="uinput", GROUP="uinput", MODE="0660",' \
+     'OPTIONS+="static_node=uinput"' \
+     | sudo tee /etc/udev/rules.d/99-uinput.rules
+   ```
+
+1. Load the kernel module:
+
+   ```bash
+   sudo modprobe uinput
+   ```
+
+1. Reload udev rules:
+
+   ```bash
+   sudo udevadm control --reload-rules
+   sudo udevadm trigger
+   ```
+
+1. Start a new login session, or refresh the current shell group list:
+
+   ```bash
+   newgrp uinput
+   ```
+
+   > [!TIP]
+   >
+   > Logging out and back in is the cleanest way to pick up the new group.
+
+## Verify
+
+- Confirm the node exists and the group is correct:
+
+  ```bash
+  ls -l /dev/uinput
+  ```
+
+- Expected shape:
+
+  ```text
+  crw-rw---- 1 root uinput 10, <minor> <MMM DD HH:MM> /dev/uinput
+  ```