fix(ui): clean up theme selector and migration for single-theme setup

- Remove dead code in migrateOldTheme() that set Theme parameter for
  KindredCreate.yaml, which no longer exists in the Stylesheets build
- Remove orphaned Classic.yaml and KindredCreate.yaml parameter files
  from Stylesheets CMakeLists and from disk
- Remove unused includes in ThemeSelectorWidget.cpp (QApplication,
  QEvent, Gui/Application.h)

src/Gui/StartupProcess.cpp

@@ -341,17 +341,6 @@ void StartupPostProcess::migrateOldTheme(const std::string& style)
     if (style == "FreeCAD Light.qss" || style == "FreeCAD Dark.qss") {
         prefPackManager->apply("KindredCreate");
     }
-
-    // Ensure the Theme parameter is set for KindredCreate so the style
-    // parameter YAML file (parameters/KindredCreate.yaml) is found.
-    if (style == "KindredCreate.qss") {
-        auto hGrp = App::GetApplication().GetParameterGroupByPath(
-            "User parameter:BaseApp/Preferences/MainWindow"
-        );
-        if (hGrp->GetASCII("Theme", "Classic") == "Classic") {
-            hGrp->SetASCII("Theme", "KindredCreate");
-        }
-    }
 }
 
 void StartupPostProcess::checkOpenGL()

src/Gui/Stylesheets/CMakeLists.txt

@@ -6,8 +6,6 @@ SET(Stylesheets_Files
 )
 
 SET(Parameters_Files
-    "parameters/Classic.yaml"
-    "parameters/KindredCreate.yaml"
 )
 
 SET(Overlay_Stylesheets_Files

src/Gui/Stylesheets/parameters/Classic.yaml

@@ -1,85 +0,0 @@
-# KindredCreate theme parameters - Catppuccin Mocha palette
-# Used by FreeCAD.qss and overlay stylesheets for token substitution
-
-# Primary surfaces
-PrimaryColor: "#1e1e2e"
-PrimaryColorDarken2: "#181825"
-DialogBackgroundColor: "#1e1e2e"
-GeneralBackgroundColor: "#1e1e2e"
-GeneralAlternateBackgroundColor: "#181825"
-
-# Text
-TextForegroundColor: "#cdd6f4"
-TextDisabledColor: "#6c7086"
-TextUrlColor: "#89b4fa"
-TextSelectBackgroundColor: "#585b70"
-
-# Input fields
-TextEditFieldBackgroundColor: "#313244"
-InputFieldBorderRadius: "2px"
-
-# Borders
-GeneralBorderColor: "#45475a"
-GeneralBorderHoverColor: "#585b70"
-
-# Buttons
-ButtonTopBackgroundColor: "#313244"
-ButtonBottomBackgroundColor: "#313244"
-ButtonBorderColor: "#45475a"
-DefaultButtonTopBackgroundColor: "#cba6f7"
-DefaultButtonBottomBackgroundColor: "#cba6f7"
-DefaultButtonBorderColor: "#cba6f7"
-CheckedButtonTopBackgroundColor: "#45475a"
-CheckedButtonBottomBackgroundColor: "#45475a"
-
-# Accent
-AccentColor: "#cba6f7"
-AccentBackgroundColor: "#45475a"
-AccentHoverColor: "#b4befe"
-
-# Interactive states
-GeneralBackgroundHoverColor: "#313244"
-GeneralDisabledBackgroundColor: "#181825"
-GeneralHeaderBackgroundColor: "#313244"
-
-# Grid
-GeneralGridLinesColor: "#313244"
-3DViewBackgroundRefColor: "#181825"
-
-# Groupbox
-GroupboxBackgroundColor: "#1e1e2e"
-GroupboxBorderColor: "#45475a"
-
-# Menu
-MenuBackgroundColor: "#181825"
-
-# Scrollbar
-ScrollbarBackgroundColor: "#181825"
-
-# Tabs
-TabbarBackgroundColor: "#181825"
-ActiveTabBackgroundColor: "#1e1e2e"
-InActiveTabBackgroundColor: "#313244"
-
-# Checkbox and radio
-CheckBoxBackgroundColor: "#313244"
-CheckBoxBorderColor: "#585b70"
-RadioButtonBackgroundColor: "#313244"
-RadioButtonBorderColor: "#585b70"
-
-# Toolbar
-ToolbarButtonsPadding: "4px"
-
-# Icons
-IconsLocationFolderName: "images_classic"
-StylesheetIconsColor: "white"
-
-# Sketcher constraint colors
-SketcherFullyConstrainedColor: "#a6e3a1"
-SketcherUnderConstrainedColor: "#f9e2af"
-SketcherConflictingConstraintsColor: "#f38ba8"
-SketcherRedundantConstraintsColor: "#fab387"
-SketcherMalformedConstraintsColor: "#f38ba8"
-SketcherPartiallyRedundantConstraintsColor: "#fab387"
-SketcherSolverFailedColor: "#f38ba8"
-SketcherEmptySketchColor: "#6c7086"

src/Gui/Stylesheets/parameters/KindredCreate.yaml

@@ -1,85 +0,0 @@
-# KindredCreate theme parameters - Catppuccin Mocha palette
-# Used by FreeCAD.qss and overlay stylesheets for token substitution
-
-# Primary surfaces
-PrimaryColor: "#1e1e2e"
-PrimaryColorDarken2: "#181825"
-DialogBackgroundColor: "#1e1e2e"
-GeneralBackgroundColor: "#1e1e2e"
-GeneralAlternateBackgroundColor: "#181825"
-
-# Text
-TextForegroundColor: "#cdd6f4"
-TextDisabledColor: "#6c7086"
-TextUrlColor: "#89b4fa"
-TextSelectBackgroundColor: "#585b70"
-
-# Input fields
-TextEditFieldBackgroundColor: "#313244"
-InputFieldBorderRadius: "2px"
-
-# Borders
-GeneralBorderColor: "#45475a"
-GeneralBorderHoverColor: "#585b70"
-
-# Buttons
-ButtonTopBackgroundColor: "#313244"
-ButtonBottomBackgroundColor: "#313244"
-ButtonBorderColor: "#45475a"
-DefaultButtonTopBackgroundColor: "#cba6f7"
-DefaultButtonBottomBackgroundColor: "#cba6f7"
-DefaultButtonBorderColor: "#cba6f7"
-CheckedButtonTopBackgroundColor: "#45475a"
-CheckedButtonBottomBackgroundColor: "#45475a"
-
-# Accent
-AccentColor: "#cba6f7"
-AccentBackgroundColor: "#45475a"
-AccentHoverColor: "#b4befe"
-
-# Interactive states
-GeneralBackgroundHoverColor: "#313244"
-GeneralDisabledBackgroundColor: "#181825"
-GeneralHeaderBackgroundColor: "#313244"
-
-# Grid
-GeneralGridLinesColor: "#313244"
-3DViewBackgroundRefColor: "#181825"
-
-# Groupbox
-GroupboxBackgroundColor: "#1e1e2e"
-GroupboxBorderColor: "#45475a"
-
-# Menu
-MenuBackgroundColor: "#181825"
-
-# Scrollbar
-ScrollbarBackgroundColor: "#181825"
-
-# Tabs
-TabbarBackgroundColor: "#181825"
-ActiveTabBackgroundColor: "#1e1e2e"
-InActiveTabBackgroundColor: "#313244"
-
-# Checkbox and radio
-CheckBoxBackgroundColor: "#313244"
-CheckBoxBorderColor: "#585b70"
-RadioButtonBackgroundColor: "#313244"
-RadioButtonBorderColor: "#585b70"
-
-# Toolbar
-ToolbarButtonsPadding: "4px"
-
-# Icons
-IconsLocationFolderName: "images_classic"
-StylesheetIconsColor: "white"
-
-# Sketcher constraint colors
-SketcherFullyConstrainedColor: "#a6e3a1"
-SketcherUnderConstrainedColor: "#f9e2af"
-SketcherConflictingConstraintsColor: "#f38ba8"
-SketcherRedundantConstraintsColor: "#fab387"
-SketcherMalformedConstraintsColor: "#f38ba8"
-SketcherPartiallyRedundantConstraintsColor: "#fab387"
-SketcherSolverFailedColor: "#f38ba8"
-SketcherEmptySketchColor: "#6c7086"

src/Mod/Start/Gui/ThemeSelectorWidget.cpp

@@ -21,8 +21,6 @@
  *                                                                          *
  ***************************************************************************/
 
-#include <QApplication>
-#include <QEvent>
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QString>
@@ -30,7 +28,6 @@
 
 #include "ThemeSelectorWidget.h"
 #include <gsl/pointers>
-#include <Gui/Application.h>
 #include <Gui/PreferencePackManager.h>
 
 using namespace StartGui;