Add Arch Wayland dotfiles: sway/waybar/kitty/nvim/zsh, idempotent installer

Auto-adapts sway workspace routing to however many monitors are
connected (laptop vs. desktop) instead of hardcoding output names.

config/sway/scripts/select-workspace.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+slot=${1:-}
+action=${2:-select}
+
+if [[ ! "$slot" =~ ^([1-9]|10)$ ]]; then
+  printf 'Usage: %s <1-10> [select|move]\n' "${0##*/}" >&2
+  exit 2
+fi
+
+# Outputs are ordered left-to-right by position, not by name, so this works
+# unmodified whether there is one output (laptop) or several (desktop):
+# the focused output's rank in that order selects its block of 10 workspaces.
+outputs=$(swaymsg -t get_outputs -r | jq -c 'sort_by(.rect.x)')
+index=$(jq -r '[.[] | .focused] | index(true)' <<<"$outputs")
+if [[ "$index" == null ]]; then
+  printf 'No focused output found\n' >&2
+  exit 1
+fi
+workspace=$((slot + index * 10))
+
+case "$action" in
+  select) swaymsg workspace number "$workspace" >/dev/null ;;
+  move)
+    swaymsg move container to workspace number "$workspace" >/dev/null
+    ;;
+  *)
+    printf 'Unknown action: %s\n' "$action" >&2
+    exit 2
+    ;;
+esac