support kind 42 chat messages

Changelog-Added: Support kind 42 chat messages (ArcadeCity).
Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/HomeModel.swift

@@ -86,6 +86,7 @@ class HomeModel: ObservableObject {
         }
 
         switch kind {
+        case .chat: fallthrough
         case .text:
             handle_text_event(sub_id: sub_id, ev)
         case .contacts:

damus/Models/Mentions.swift

@@ -279,7 +279,7 @@ func post_to_event(post: NostrPost, privkey: String, pubkey: String) -> NostrEve
     let post_blocks = parse_post_blocks(content: post.content)
     let post_tags = make_post_tags(post_blocks: post_blocks, tags: tags)
     let content = render_blocks(blocks: post_tags.blocks)
-    let new_ev = NostrEvent(content: content, pubkey: pubkey, kind: 1, tags: post_tags.tags)
+    let new_ev = NostrEvent(content: content, pubkey: pubkey, kind: post.kind.rawValue, tags: post_tags.tags)
     new_ev.calculate_id()
     new_ev.sign(privkey: privkey)
     return new_ev

damus/Models/Post.swift

@@ -8,8 +8,21 @@
 import Foundation
 
 struct NostrPost {
+    let kind: NostrKind
     let content: String
     let references: [ReferencedId]
+    
+    init (content: String, references: [ReferencedId]) {
+        self.content = content
+        self.references = references
+        self.kind = .text
+    }
+    
+    init (content: String, references: [ReferencedId], kind: NostrKind) {
+        self.content = content
+        self.references = references
+        self.kind = kind
+    }
 }
 
 // TODO: parse nostr:{e,p}:pubkey uris as well