feature(software): add signal-desktop electron app

Reviewed-on: #94

INSTALLATION.md

@@ -149,6 +149,23 @@ $ sudo sbctl enroll-keys
   Don't force it, either trust exactly those with `--tpm-eventlog` or
   microsoft's keys with `--microsoft`. Without either, the firmware may not
   start the device, in the worst case the machine doesn't boot at all.
+- Check what sbctl found first, a real option ROM has a PCI device path:
+```bash
+$ sudo nix shell nixpkgs#tpm2-tools -c tpm2_eventlog /sys/kernel/security/tpm0/binary_bios_measurements | grep -A14 "EV_EFI_BOOT_SERVICES_DRIVER"
+```
+- Paths starting with `0407` (firmware volume) are drivers from the firmware
+  itself, not option ROMs (e.g. on the ThinkPad). `--tpm-eventlog` trusts
+  exactly those, after a firmware update they may need to be enrolled again
+  (disable Secure Boot, `sbctl enroll-keys --tpm-eventlog`)
+- Without an integrated gpu (argon), the gpu's option ROM draws the firmware
+  setup too, use `--microsoft` there, a refused gpu means no picture at all
+- On the Framework (krypton), keep the firmware's built-in OEM certificates
+  with `--firmware-builtin`, vendor firmware updates may need them. If an
+  update fails or the keys were enrolled without them, erase the keys in the
+  firmware again (Setup Mode) and re-enroll:
+```bash
+$ sudo sbctl enroll-keys --firmware-builtin
+```
 
 6. enable Secure Boot in the firmware and set a firmware password, then check
 ```bash

hosts/argon/configuration.nix

@@ -12,6 +12,7 @@
     ../../modules/nixos/data-drives.nix
     ../../modules/nixos/gnupg.nix
     ../../modules/nixos/greetd.nix
+    ../../modules/nixos/lanzaboote.nix
     ../../modules/nixos/locales.nix
     ../../modules/nixos/networking.nix
     ../../modules/nixos/niri.nix
@@ -23,6 +24,7 @@
     ../../modules/nixos/settings.nix
     ../../modules/nixos/steam.nix
     ../../modules/nixos/thunar.nix
+    ../../modules/nixos/tpm-unlock.nix
     ../../modules/nixos/users.nix
     ../../modules/nixos/vial.nix
   ];

hosts/krypton/configuration.nix

@@ -32,6 +32,13 @@
   # host-specific niri config (input devices, laptop binds)
   home-manager.users.aaron.imports = [ ./niri.nix ];
 
+  # hidpi panel (2880x1920): the sddm greeter runs in weston, which doesn't scale
+  services.displayManager.sddm.settings.General.GreeterEnvironment = "QT_SCALE_FACTOR=2";
+
+  # bigger boot menu font, mode found with "r" in the menu; mode 6 is beyond
+  # what boot.loader.systemd-boot.consoleMode accepts, so set via lanzaboote
+  boot.lanzaboote.settings.console-mode = "6";
+
   networking.hostName = "krypton";
   system.stateVersion = "26.05"; # don't change
 }

hosts/neon/configuration.nix

@@ -17,6 +17,7 @@
     ../../modules/nixos/certificates.nix
     ../../modules/nixos/docker.nix
     ../../modules/nixos/gnupg.nix
+    ../../modules/nixos/lanzaboote.nix
     ../../modules/nixos/locales.nix
     ../../modules/nixos/networking.nix
     ../../modules/nixos/niri.nix
@@ -28,6 +29,7 @@
     ../../modules/nixos/services.nix
     ../../modules/nixos/settings.nix
     ../../modules/nixos/steam.nix
+    ../../modules/nixos/tpm-unlock.nix
     ../../modules/nixos/users.nix
     ../../modules/nixos/vial.nix
   ];

modules/home-manager/programs.nix

@@ -7,6 +7,7 @@
     discord
     fastfetch
     keepassxc
+    signal-desktop
     teamspeak6-client
     typst
     zathura

modules/nixos/bootloader.nix

@@ -4,6 +4,8 @@
   # set bootloader to systemd
   boot.loader = {
     systemd-boot.enable = true;
+    # no kernel command line editing at the boot menu (e.g. init=/bin/sh)
+    systemd-boot.editor = false;
     efi.canTouchEfiVariables = true;
   };