Reset glyph to archetype default when selection changes

Selecting a different archetype in the editor now updates the active
glyph to that archetype's default_glyph(), keeping the visual preview
in sync with the selected behavior type.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main.rs

@@ -175,11 +175,13 @@ impl eframe::App for App {
                                             }
                                             if cell_resp.clicked() {
                                                 self.editor.selected = archetype;
+                                                self.editor.glyph    = archetype.default_glyph();
                                             }
                                             if ui.selectable_label(is_selected, archetype.name())
                                                 .clicked()
                                             {
                                                 self.editor.selected = archetype;
+                                                self.editor.glyph    = archetype.default_glyph();
                                             }
                                         });
                                     }