Hide "become a sustainer" button if you're already a sustainer

ts/state/ducks/items.ts

@@ -36,6 +36,8 @@ export type ItemsStateType = {
   readonly preferredLeftPaneWidth?: number;
 
   readonly preferredReactionEmoji?: Array<string>;
+
+  readonly areWeASubscriber?: boolean;
 };
 
 // Actions

ts/state/selectors/items.ts

@@ -20,6 +20,12 @@ const DEFAULT_PREFERRED_LEFT_PANE_WIDTH = 320;
 
 export const getItems = (state: StateType): ItemsStateType => state.items;
 
+export const getAreWeASubscriber = createSelector(
+  getItems,
+  ({ areWeASubscriber }: Readonly<ItemsStateType>): boolean =>
+    Boolean(areWeASubscriber)
+);
+
 export const getUserAgent = createSelector(
   getItems,
   (state: ItemsStateType): string => state.userAgent as string

ts/state/smart/ContactModal.tsx

@@ -7,6 +7,7 @@ import type { PropsDataType } from '../../components/conversation/ContactModal';
 import { ContactModal } from '../../components/conversation/ContactModal';
 import type { StateType } from '../reducer';
 
+import { getAreWeASubscriber } from '../selectors/items';
 import { getIntl, getTheme } from '../selectors/user';
 import { getBadgesSelector } from '../selectors/badges';
 import { getConversationSelector } from '../selectors/conversations';
@@ -35,6 +36,7 @@ const mapStateToProps = (state: StateType): PropsDataType => {
   }
 
   return {
+    areWeASubscriber: getAreWeASubscriber(state),
     areWeAdmin,
     badges: getBadgesSelector(state)(contact.badges),
     contact,

ts/state/smart/ConversationDetails.tsx

@@ -13,6 +13,7 @@ import {
   getConversationByUuidSelector,
 } from '../selectors/conversations';
 import { getGroupMemberships } from '../../util/getGroupMemberships';
+import { getAreWeASubscriber } from '../selectors/items';
 import { getIntl, getTheme } from '../selectors/user';
 import type { MediaItemType } from '../../types/MediaItem';
 import {
@@ -82,6 +83,7 @@ const mapStateToProps = (
 
   return {
     ...props,
+    areWeASubscriber: getAreWeASubscriber(state),
     badges,
     canEditGroupInfo,
     candidateContactsToAdd,