Switch to System font to fix emoji rendering

src/view/com/post-thread/PostThreadItem.tsx

@@ -356,7 +356,7 @@ const styles = StyleSheet.create({
     maxWidth: 240,
   },
   postText: {
-    fontFamily: 'Helvetica Neue',
+    fontFamily: 'System',
     fontSize: 16,
     lineHeight: 20.8, // 1.3 of 16px
   },

src/view/com/post/Post.tsx

@@ -206,7 +206,7 @@ const styles = StyleSheet.create({
     paddingBottom: 8,
   },
   postText: {
-    fontFamily: 'Helvetica Neue',
+    fontFamily: 'System',
     fontSize: 16,
     lineHeight: 20.8, // 1.3 of 16px
   },

src/view/com/posts/FeedItem.tsx

@@ -249,7 +249,7 @@ const styles = StyleSheet.create({
     minHeight: 36,
   },
   postText: {
-    fontFamily: 'Helvetica Neue',
+    fontFamily: 'System',
     fontSize: 16,
     lineHeight: 20.8, // 1.3 of 16px
   },

src/view/com/util/RichText.tsx

@@ -98,13 +98,3 @@ function* toSegments(text: string, entities: Entity[]) {
     yield text.slice(cursor, text.length)
   }
 }
-
-function stripUsername(v: string): string {
-  return v.trim().replace('@', '')
-}
-
-function isSameLink(a: string, b: string) {
-  a = a.startsWith('http') ? a : `https://${a}`
-  b = b.startsWith('http') ? b : `https://${b}`
-  return a === b
-}