refactor: Decoupling chat architecture (#367)

* refactor: Migrate tests to Qt Creator plugin framework and update llmqore transports

* refactor: Move conversation history into IDE-free session library

* refactor: Extract turn context assembly behind injected ports

* build: Add RunQodeAssistTests target for the plugin test suite

* refactor: Route the chat through a Session and ChatBackend seam

sources/session/FileEditPayload.hpp

@@ -0,0 +1,18 @@
+// Copyright (C) 2026 Petr Mironychev
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Additional attribution terms under GPLv3 §7(b) apply — see LICENSE
+
+#pragma once
+
+#include <QJsonObject>
+#include <QString>
+
+#include <optional>
+
+namespace QodeAssist::Session {
+
+bool isFileEditPayload(const QString &text);
+std::optional<QJsonObject> parseFileEditPayload(const QString &text);
+QString encodeFileEditPayload(const QJsonObject &payload);
+
+} // namespace QodeAssist::Session