feat(translate): add per-series glossary with auto extraction

src/translate/glossarystore.h

@@ -0,0 +1,20 @@
+// SPDX-FileCopyrightText: 2026 Tri Vo Khac
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <QList>
+#include <QString>
+
+class GlossaryStore
+{
+public:
+    struct Entry { QString source; QString target; };
+    struct Glossary { QString directory; QList<Entry> entries; };
+
+    static Glossary load(const QString &directory);
+    static bool save(const Glossary &glossary, QString *error = nullptr);
+    static Glossary merge(const Glossary &existing, const QList<Entry> &additions);
+    static QString serialize(const Glossary &glossary);
+    static QString pathForDirectory(const QString &directory);
+};