feat(mobx): start work on migrations

src/components/settings/AppearanceShims.tsx

@@ -34,7 +34,13 @@ import { ThemeBaseSelector } from "./appearance/ThemeBaseSelector";
 export const ThemeBaseSelectorShim = observer(() => {
     const theme = useApplicationState().settings.theme;
     return (
-        <ThemeBaseSelector value={theme.getBase()} setValue={theme.setBase} />
+        <ThemeBaseSelector
+            value={theme.isModified() ? undefined : theme.getBase()}
+            setValue={(base) => {
+                theme.setBase(base);
+                theme.reset();
+            }}
+        />
     );
 });
 
@@ -97,10 +103,6 @@ export const ThemeCustomCSSShim = observer(() => {
     );
 });
 
-export const ThemeImporterShim = observer(() => {
-    return <a></a>;
-});
-
 /**
  * Component providing a way to switch between compact and normal message view.
  */

src/components/settings/appearance/EmojiSelector.tsx

@@ -92,7 +92,7 @@ export function EmojiSelector({ value, setValue }: Props) {
                         <div
                             class="button"
                             onClick={() => setValue("mutant")}
-                            data-active={value === "mutant"}>
+                            data-active={!value || value === "mutant"}>
                             <img
                                 loading="eager"
                                 src={mutantSVG}