Add alvin-install TUI installer, fix NetworkManager boot

- New gum-based installer script (alvin-install) with LUKS encryption,
  nmtui networking, disk selector, user/git config, and CachyOS repo setup
- Replace NetworkManager full unit file with symlink for consistency
- Add alvin-install reference to MOTD
- Add file_permissions entry in profiledef.sh
- Fix localrepo path case in pacman.conf

airootfs/etc/systemd/system/multi-user.target.wants/NetworkManager.service

@@ -1,30 +0,0 @@
-[Unit]
-Description=Network Manager
-Documentation=man:NetworkManager.conf(5)
-Wants=NetworkManager-wait-online.service
-After=sysinit.target network-pre.target
-Wants=network-pre.target
-Before=network-online.target remote-fs.target
-After=network-pre.target
-BindsTo=sys-subsystem-net-devices.target
-After=sys-subsystem-net-devices.target
-
-[Service]
-Type=dbus
-BusName=org.freedesktop.NetworkManager
-ExecCondition=/usr/bin/test -x /usr/bin/NetworkManager
-ExecReload=/usr/bin/kill -HUP $MAINPID
-ExecStart=/usr/bin/NetworkManager --no-daemon
-Restart=on-failure
-KillMode=process
-CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_BIND_SERVICE CAP_SYS_PTRACE CAP_DAC_READ_SEARCH CAP_DAC_OVERRIDE
-LockPersonality=yes
-MemoryDenyWriteExecute=yes
-ProtectHome=yes
-ProtectSystem=yes
-RestrictNamespaces=yes
-RestrictRealtime=yes
-SystemCallFilter=@system-service
-
-[Install]
-WantedBy=multi-user.target

airootfs/etc/systemd/system/multi-user.target.wants/NetworkManager.service

@@ -0,0 +1 @@
+/usr/lib/systemd/system/NetworkManager.service