fix: selection bug

ts/src/browser.ts

@@ -763,7 +763,7 @@ const MetaPanel: m.Component = {
                 activeSecIndex !== null && setSectionType(activeSecIndex, (e.target as HTMLSelectElement).value),
             },
               Object.values(MonoDisplay.SectionTypeToString).map(name =>
-                m("option", { value: name }, name)
+                m("option", { value: name, selected: name === MonoDisplay.SectionTypeToString[section.sectionType] }, name)
               )
             )
           : m("span.meta-val.green", "-"),