itemactions: Add context menu actions to hide and unhide files using .hidden

Summary:
This patch introduces context menu actions that allow users to hide or unhide selected files by editing the .hidden file in their parent directories.

What this patch does:
- Implemented HideFileItemAction plugin based on KAbstractFileItemActionPlugin
- Plugin is disabled by default unless explicitly enabled in kservicemenurc via the hidefileitemaction key
- "Hide" action adds selected file names to the .hidden file, avoiding duplicates
- "Unhide" action removes selected file names from the .hidden file
- Action visibility logic:
	- If only visible or only hidden files are selected, only the relevant action is shown
	- If both are selected, both "Hide" and "Unhide" actions are shown
- Write permission checks ensure actions are disabled if the .hidden file cannot be modified
- Optimized redundant path computations by calculating parent directory and .hidden file paths once and reusing them

1 files changed, 26 insertions, 0 deletions

diff --git a/src/itemactions/hidefileitemaction.h b/src/itemactions/hidefileitemaction.h
new file mode 100644
index 000000000..565f0d563
--- /dev/null
+++ b/src/itemactions/hidefileitemaction.h
@@ -0,0 +1,26 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Kostiantyn Korchuhanov <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HIDEFILEITEMACTION_H
+#define HIDEFILEITEMACTION_H
+
+#include <KAbstractFileItemActionPlugin>
+#include <KFileItemListProperties>
+#include <QAction>
+#include <QList>
+#include <QWidget>
+
+class HideFileItemAction : public KAbstractFileItemActionPlugin
+{
+    Q_OBJECT
+
+public:
+    HideFileItemAction(QObject *parent);
+
+    QList<QAction *> actions(const KFileItemListProperties &fileItemInfos, QWidget *parentWidget) override;
+};
+
+#endif // HIDEFILEITEMACTION_H