OmaPhoto 1.0.0: the Linux port of Compositor

A layered image editor for Linux and Omarchy, ported from Compositor
(github.com/robbietilton/Compositor), whose Swift source is its
specification. It reads and writes Compositor's .comp projects.

Packages for Ubuntu, Fedora and Arch come from the release workflow;
scripts/install/ holds one install script per distribution family,
and flake.nix serves NixOS.

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/install/nixos.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+# Installs OmaPhoto on NixOS from its flake.
+set -euo pipefail
+if ! command -v nix >/dev/null; then
+    echo "This script needs Nix; NixOS carries it." >&2
+    exit 1
+fi
+if [ "$(uname -m)" != x86_64 ]; then
+    echo "OmaPhoto's flake builds for x86_64 alone." >&2
+    exit 1
+fi
+nix --extra-experimental-features "nix-command flakes" profile install github:ZacharyZhang-NY/OmaPhoto