feat(nixos): add multi-arch support and refactor system configs

- add aarch64-linux to supported systems (flake + pkgs)
- refactor host definitions into tty/desktop/laptop configurations
- introduce sharedModules to reduce duplication
- split system modules into base, gui, and laptop groups
- add headless (tty) configuration

feat(fish): add Ctrl+Delete and Alt+Delete bindings
- Ctrl+Delete → kill-word
- Alt+Delete → kill-token

chore(hosts): remove explicit hostname from aesthetic

chore(services): remove forced disable of speechd

home/terminal/shell/fish.nix

@@ -37,7 +37,9 @@
           # Custom bindings
           for mode in insert default
             bind -M $mode ctrl-backspace backward-kill-word
+            bind -M $mode ctrl-delete kill-word
             bind -M $mode alt-backspace backward-kill-token
+            bind -M $mode alt-delete kill-token
             bind -M $mode ctrl-z undo
           end
           bind -M insert \cx\ce edit_command_buffer
@@ -173,8 +175,6 @@ end
         alias cleanram="sudo sh -c 'sync; echo 3 > /proc/sys/vm/drop_caches'"
         alias trimall="sudo fstrim -va"
         alias c="clear"
-        alias test-build="sudo nixos-rebuild test --flake /etc/nixos#aesthetic"
-        alias switch-build="sudo nixos-rebuild switch --flake /etc/nixos#aesthetic"
         alias add="git add ."
         alias commit="git commit"
         alias push="git push"