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>

src/Document/SelectionClipboard.h

@@ -0,0 +1,18 @@
+#pragma once
+#include <QImage>
+#include <QPointF>
+#include <QRectF>
+
+// Pixels copied from the canvas, with where they came from.
+struct PixelClipboard {
+    QImage image;
+    QPointF origin;
+    // The clipboard's changes when written; more means another copy since.
+    int changeCount;
+};
+
+// Swift's (image, region) tuple: pixels and their canvas bounds.
+struct CopiedPixels {
+    QImage image;
+    QRectF region;
+};