[PM-11691] Remove Nord and Solarized Dark from extension (#11013)

* remove nord and solarized dark from AppearanceV2 component
- This component already behind the extension refresh feature flag

* update the users theme to system when nord or solarized dark is selected

* For desktop, still allow all theme types by overriding the default theme service.

* change theme on the fly rather than updating local state.

- When the feature flag is removed then a migration will have to take place

libs/common/src/platform/theming/theme-state.service.ts

@@ -1,5 +1,7 @@
-import { Observable, map } from "rxjs";
+import { Observable, combineLatest, map } from "rxjs";
 
+import { FeatureFlag } from "../../enums/feature-flag.enum";
+import { ConfigService } from "../abstractions/config/config.service";
 import { ThemeType } from "../enums";
 import { GlobalStateProvider, KeyDefinition, THEMING_DISK } from "../state";
 
@@ -16,17 +18,32 @@ export abstract class ThemeStateService {
   abstract setSelectedTheme(theme: ThemeType): Promise<void>;
 }
 
-const THEME_SELECTION = new KeyDefinition<ThemeType>(THEMING_DISK, "selection", {
+export const THEME_SELECTION = new KeyDefinition<ThemeType>(THEMING_DISK, "selection", {
   deserializer: (s) => s,
 });
 
 export class DefaultThemeStateService implements ThemeStateService {
   private readonly selectedThemeState = this.globalStateProvider.get(THEME_SELECTION);
 
-  selectedTheme$ = this.selectedThemeState.state$.pipe(map((theme) => theme ?? this.defaultTheme));
+  selectedTheme$ = combineLatest([
+    this.selectedThemeState.state$,
+    this.configService.getFeatureFlag$(FeatureFlag.ExtensionRefresh),
+  ]).pipe(
+    map(([theme, isExtensionRefresh]) => {
+      // The extension refresh should not allow for Nord or SolarizedDark
+      // Default the user to their system theme
+      if (isExtensionRefresh && [ThemeType.Nord, ThemeType.SolarizedDark].includes(theme)) {
+        return ThemeType.System;
+      }
+
+      return theme;
+    }),
+    map((theme) => theme ?? this.defaultTheme),
+  );
 
   constructor(
     private globalStateProvider: GlobalStateProvider,
+    private configService: ConfigService,
     private defaultTheme: ThemeType = ThemeType.System,
   ) {}