gui: complete KF5 build with full feature parity

- Add chatblockmodel.cpp and thememanager.cpp to KF5 GUI target
- Link KF5::ConfigCore and KF5::SyntaxHighlighting to GUI
- Strip Qt6-only grouped palette syntax from QML at configure time
  (ThemeManager::applyPalette handles palette via QGuiApplication)
- Fix QStringList brace-init ambiguity in Qt5
- Fix QList::remove(pos,count) not available in Qt5 (use erase)

CMakeLists.txt

@@ -75,13 +75,21 @@ if(OLLIE_KF5)
     endif()
 
     # --- GUI App (9P-based) ---
-    configure_file(gui/main.qml ${CMAKE_CURRENT_BINARY_DIR}/gui-kf5/main.qml COPYONLY)
+    # Strip Qt6-only grouped palette syntax (palette.active.*, palette.inactive.*,
+    # palette.disabled.*) — Qt5 QML doesn't support color-group qualifiers.
+    # ThemeManager::applyPalette() sets the application palette which Qt Quick
+    # Controls 2 picks up automatically.
+    file(READ ${CMAKE_CURRENT_SOURCE_DIR}/gui/main.qml _QML_SRC)
+    string(REGEX REPLACE "[ \t]*(//[^\n]*palette[^\n]*\n|palette\\.(active|inactive|disabled)\\.[^\n]*\n)" "" _QML_SRC "${_QML_SRC}")
+    file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/gui-kf5/main.qml "${_QML_SRC}")
     configure_file(gui/qml.qrc ${CMAKE_CURRENT_BINARY_DIR}/gui-kf5/qml.qrc COPYONLY)
     qt5_add_resources(GUI_KF5_QRC ${CMAKE_CURRENT_BINARY_DIR}/gui-kf5/qml.qrc)
     add_executable(ollie-gui
         gui/main.cpp
         gui/ollie9pclient.cpp
         gui/ninepconnection.cpp
+        gui/chatblockmodel.cpp
+        gui/thememanager.cpp
         gui/streamfsm.cpp
         ${GUI_KF5_QRC}
     )
@@ -91,6 +99,8 @@ if(OLLIE_KF5)
         Qt5::Widgets
         Qt5::Quick
         Qt5::QuickControls2
+        KF5::ConfigCore
+        KF5::SyntaxHighlighting
     )
 
     # --- Install ---

gui/chatblockmodel.cpp

@@ -157,7 +157,11 @@ void ChatBlockModel::trimFront(int keepCount)
         return;
     int removeCount = m_blocks.size() - keepCount;
     beginRemoveRows(QModelIndex(), 0, removeCount - 1);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     m_blocks.remove(0, removeCount);
+#else
+    m_blocks.erase(m_blocks.begin(), m_blocks.begin() + removeCount);
+#endif
     endRemoveRows();
     emit countChanged();
 }

gui/ollie9pclient.cpp

@@ -502,7 +502,7 @@ void Ollie9pClient::loadRootAgents()
         m_rootAgentsLoaded = true;
         emit availableAgentsChanged();
     } else {
-        m_availableAgents = {"default"};
+        m_availableAgents = QStringList() << QStringLiteral("default");
         m_rootAgentsLoaded = true;
         emit availableAgentsChanged();
     }