Preserve selection during auto-refresh

- Only refresh status model when git output actually changes (skip
  beginResetModel/endResetModel if raw output is identical)
- Filesystem watcher triggers updateStatus only, not refreshAll —
  branch/stash/worktree lists only rebuild on explicit user actions
- Branch list refreshes on HEAD file change (branch switch) with delay
  to avoid interrupting interactions

gitplusplus.cpp

@@ -430,7 +430,7 @@ GitPlusPlusView::GitPlusPlusView(GitPlusPlusPlugin *plugin, KTextEditor::MainWin
     // Debounce timer for filesystem changes (avoid spamming refreshes)
     m_fsDebounce.setSingleShot(true);
     m_fsDebounce.setInterval(500);
-    connect(&m_fsDebounce, &QTimer::timeout, this, &GitPlusPlusView::refreshAll);
+    connect(&m_fsDebounce, &QTimer::timeout, this, &GitPlusPlusView::updateStatus);
 
     // Initial refresh
     QMetaObject::invokeMethod(this, &GitPlusPlusView::updateStatus, Qt::QueuedConnection);
@@ -549,7 +549,7 @@ void GitPlusPlusView::setupFileWatcher()
     connect(m_watcher, &QFileSystemWatcher::directoryChanged, this, [this](const QString &) {
         m_fsDebounce.start();
     });
-    // Still watch individual files as a fallback for systems where dir watching is coarse
+    // Watch HEAD file specifically — changes indicate branch switch
     QString indexFile = gitDir + QStringLiteral("/index");
     QString headFile = gitDir + QStringLiteral("/HEAD");
     QStringList filePaths;
@@ -557,7 +557,7 @@ void GitPlusPlusView::setupFileWatcher()
     if (QFileInfo::exists(headFile)) filePaths << headFile;
     if (!filePaths.isEmpty()) {
         m_watcher->addPaths(filePaths);
-        connect(m_watcher, &QFileSystemWatcher::fileChanged, this, [this](const QString &path) {
+        connect(m_watcher, &QFileSystemWatcher::fileChanged, this, [this, headFile](const QString &path) {
             // Re-add: atomic renames remove the watch
             if (!m_watcher->files().contains(path)) {
                 QTimer::singleShot(200, this, [this, path]() {
@@ -566,6 +566,10 @@ void GitPlusPlusView::setupFileWatcher()
                 });
             }
             m_fsDebounce.start();
+            // HEAD change means branch switch — refresh branches
+            if (path == headFile) {
+                QTimer::singleShot(600, this, [this]() { refreshBranches(); });
+            }
         });
     }
 }

gitstatusmodel.cpp

@@ -153,6 +153,10 @@ Qt::ItemFlags GitStatusModel::flags(const QModelIndex &index) const
 
 void GitStatusModel::parseStatus(const QByteArray &raw)
 {
+    if (raw == m_lastRaw)
+        return;
+    m_lastRaw = raw;
+
     beginResetModel();
 
     for (int i = 0; i < NodeCount; ++i)

gitstatusmodel.h

@@ -61,6 +61,7 @@ public:
 private:
     static constexpr quintptr TopLevelId = 0xFFFFFFFF;
 
+    QByteArray m_lastRaw;
     QList<GitStatusEntry> m_entries[NodeCount];
     QString m_nodeNames[NodeCount];
     QIcon m_nodeIcons[NodeCount];