Users and permissions: accounts, login, enforced file permissions, setuid, su, passwd, doas

The kernel now checks owner/group/other on open, create, unlink, rename, exec
and path search; honours set-user-id and set-group-id; restricts kill, mount,
reboot and mknod; keeps supplementary groups; and implements chown. devtmpfs
nodes carry owners and modes that chmod/chown keep. Terminals run login, the
image has root and schos, X starts as the ordinary user.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao

docs/Website/docs.js

@@ -35,6 +35,8 @@
       ["architecture/terminals.md",   "Virtual terminals"],
       ["architecture/devices.md",     "Device model"],
       ["architecture/usb.md",         "USB"],
+      ["architecture/udev.md",        "udev"],
+      ["architecture/users.md",       "Users and permissions"],
       ["architecture/graphics.md",    "Graphics"],
       ["architecture/audio.md",       "Audio"],
       ["architecture/networking.md",  "Networking"],