Fix dark-theme backgrounds across device, HMS, and AMS UI on macOS

Give previously-bare panels a keyed background so the existing dark-UI walk
can theme them. Runtime-created widgets (HMS items, device firmware/nozzle
panels) route their whole subtree through one UpdateDarkUIWin(this) call
instead of per-widget darkModeColorFor, which also themes their child text
and follows live light/dark switches. Extruder-card chips re-apply their
colours from Sidebar::sys_color_changed so a live switch updates them too.

src/slic3r/GUI/Plater.cpp

@@ -460,6 +460,17 @@ enum class ActionButtonType : int {
     abSendGCode
 };
 
+// Background for the extruder-group title chip and its edit buttons, matching the StaticGroup
+// interior. macOS keeps a lighter #F7F7F7 tint in light mode; dark mode uses the mapped colour.
+static wxColour extruder_group_chip_bg()
+{
+#ifdef __WXOSX__
+    if (!wxGetApp().dark_mode())
+        return wxColour("#F7F7F7");
+#endif
+    return StateColor::darkModeColorFor(*wxWHITE);
+}
+
 // Interactive title row for the sidebar extruder cards: "<title> ( <count> ) [edit]". The count shows the
 // extruder's physical nozzle count on multi-nozzle printers (hidden elsewhere, SetCount(-1)), and the
 // trailing button opens the manual nozzle-count editor when enabled (a plain dot otherwise).
@@ -468,11 +479,7 @@ class HoverLabel : public wxPanel
 public:
     HoverLabel(wxWindow *parent, const wxString &label) : wxPanel(parent, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxBORDER_NONE)
     {
-#ifdef __WXOSX__
-        SetBackgroundColour("#F7F7F7");
-#else
-        SetBackgroundColour(*wxWHITE);
-#endif
+        SetBackgroundColour(extruder_group_chip_bg());
         auto sizer = new wxBoxSizer(wxHORIZONTAL);
 
         m_label = new wxStaticText(this, wxID_ANY, label, wxDefaultPosition, wxDefaultSize, wxBORDER_NONE);
@@ -496,11 +503,7 @@ public:
 
         m_hover_btn = new ScalableButton(this, wxID_ANY, "dot");
         m_hover_btn->SetMinSize(wxSize(FromDIP(25), -1));
-#ifdef __WXOSX__
-        m_hover_btn->SetBackgroundColour("#F7F7F7");
-#else
-        m_hover_btn->SetBackgroundColour(*wxWHITE);
-#endif
+        m_hover_btn->SetBackgroundColour(extruder_group_chip_bg());
         m_hover_btn->Bind(wxEVT_COMMAND_BUTTON_CLICKED, [this](auto &evt) {
             if (m_enabled && m_hover_on_click)
                 m_hover_on_click();
@@ -550,6 +553,17 @@ public:
 
     void Rescale() { m_hover_btn->msw_rescale(); }
 
+    // Re-apply the chip colours on a live light/dark switch (they are set once at construction).
+    void sys_color_changed()
+    {
+        SetBackgroundColour(extruder_group_chip_bg());
+        m_label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#6B6B6B")));
+        for (wxStaticText *t : {m_brace_left, m_count, m_brace_right})
+            t->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#262E30")));
+        m_hover_btn->SetBackgroundColour(extruder_group_chip_bg());
+        Refresh();
+    }
+
 private:
     // Content changed: the cached best size (ours and, transitively, our ancestors') is stale,
     // and the parent must re-lay this row or the sizer keeps allocating the old width.
@@ -625,6 +639,15 @@ struct ExtruderGroup : StaticGroup
         for (int i = 0; i < 4; ++i)
             ams[i]->msw_rescale();
     }
+
+    void sys_color_changed()
+    {
+        if (hover_label)
+            hover_label->sys_color_changed();
+        if (btn_edit)
+            btn_edit->SetBackgroundColour(extruder_group_chip_bg());
+        Refresh();
+    }
 };
 
 struct Sidebar::priv
@@ -1275,11 +1298,7 @@ ExtruderGroup::ExtruderGroup(wxWindow * parent, int index, wxString const &title
     //label_ams->SetMinSize({FromDIP(70), -1});
     if (index >= 0) {
         btn_edit = new ScalableButton(this, wxID_ANY, "dot");
-#ifdef __WXOSX__
-        btn_edit->SetBackgroundColour("#F7F7F7");
-#else
-        btn_edit->SetBackgroundColour(*wxWHITE);
-#endif
+        btn_edit->SetBackgroundColour(extruder_group_chip_bg());
         btn_edit->Hide();
         btn_edit->Bind(wxEVT_COMMAND_BUTTON_CLICKED, [this, index](auto &evt) {
             PopupWindow *window = new AMSCountPopupWindow(this, index);
@@ -3866,6 +3885,10 @@ void Sidebar::sys_color_changed()
     p->image_printer->SetSize(FromDIP(PRINTER_THUMBNAIL_SIZE));
     p->image_printer_bed->SetSize(FromDIP(PRINTER_THUMBNAIL_SIZE));
 
+    for (ExtruderGroup *ext : {p->left_extruder, p->right_extruder, p->single_extruder})
+        if (ext)
+            ext->sys_color_changed();
+
     // call a kill focus event to ensure new colors applied
     for (ComboBox* combo : std::vector<ComboBox*>{p->combo_printer, p->combo_nozzle_dia, p->combo_printer_bed}){
         wxFocusEvent fakeEvent(wxEVT_KILL_FOCUS);