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>

tests/ProjectFixtures.h

@@ -0,0 +1,63 @@
+#pragma once
+#include "IO/ProjectStore.h"
+#include "RenderFixtures.h"
+#include <QDir>
+#include <QFile>
+
+// A 64x32 image: red on the left, clear right.
+inline QImage halfRed()
+{
+    QImage image = BrushRaster::context(64, 32, false);
+    for (int y = 0; y < 32; ++y) {
+        for (int x = 0; x < 32; ++x)
+            image.setPixel(x, y, qRgba(255, 0, 0, 255));
+    }
+    return image;
+}
+
+inline ImportedImage asset(const QImage &image, const QString &name)
+{
+    return ImportedImage(image, image, name);
+}
+
+// A hidden, turned, flipped image layer under a blank one.
+inline ProjectSnapshot twoLayers()
+{
+    const QUuid imageID = QUuid::createUuid(), blankID = QUuid::createUuid();
+    const LayerTransform turned{.origin = {-27.5, 88.25}, .size = {123, 47}, .rotation = 38, .flipX = true, .flipY = true,
+                                .sampling = LayerSampling::nearest};
+    const ProjectLayerRecord image{.id = imageID, .name = QStringLiteral("Paint & sky \U0001F324"), .isVisible = false, .transform = turned,
+                                   .imageFile = uuidString(imageID) + ".png"};
+    const ProjectLayerRecord blank{.id = blankID, .name = "Layer 2", .isVisible = true,
+                                   .transform = {.origin = {0, 0}, .size = {100, 80}}, .imageFile = std::nullopt};
+    return {.manifest = {.resolution = 300, .documentID = QUuid::createUuid(), .width = 100, .height = 80, .activeLayerID = blankID,
+                         .layers = {image, blank}},
+            .images = {{imageID, asset(halfRed(), "source")}}};
+}
+
+inline QByteArray contents(const QString &path)
+{
+    QFile file(path);
+    if (!file.open(QIODevice::ReadOnly))
+        throw std::runtime_error("cannot read " + path.toStdString());
+    return file.readAll();
+}
+
+inline void overwrite(const QString &path, const QByteArray &data)
+{
+    QFile file(path);
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate) || file.write(data) != data.size())
+        throw std::runtime_error("cannot write " + path.toStdString());
+}
+
+// The kind of ProjectError `body` throws, if it throws one.
+template <typename Body>
+std::optional<ProjectError::Kind> projectError(Body body)
+{
+    try {
+        body();
+    } catch (const ProjectError &error) {
+        return error.kind;
+    }
+    return std::nullopt;
+}