feat(interests): keep our own list and send it again each login

The server holds interests only for the session that set them, so a client
that does not re-send its list comes back from a reconnect with none. That
is why Nicotine+ sends its whole list at every login, and why it lowercases
each item before sending — the server matches them case-insensitively, so
two spellings would otherwise be held as two interests.

Ours now keeps the list, in one spelling, and puts it back on the wire when
a session starts; an interest set before there is a connection is kept
rather than dropped. A room's ticker board is also let go when we leave the
room, since the server sends the whole board again on the next join.

soulseek-rs-lib/src/client/operations.rs

@@ -917,6 +917,30 @@ impl Client {
                         }
                         Self::announce_child_capacity(&client_context);
                     }
+                    ClientOperation::SessionEstablished => {
+                        // Interests live in the server only for the session
+                        // that set them, so a new one starts by sending ours
+                        // again — what Nicotine+ does from its config file.
+                        let (sender, interests) = match client_context
+                            .read_safe()
+                        {
+                            Ok(ctx) => {
+                                (ctx.server_sender.clone(), ctx.own_interests())
+                            }
+                            Err(_) => continue,
+                        };
+                        let Some(sender) = sender else { continue };
+                        for item in &interests.likes {
+                            let _ = sender.send(ServerMessage::SendMessage(
+                                MessageFactory::build_add_thing_i_like(item),
+                            ));
+                        }
+                        for item in &interests.hates {
+                            let _ = sender.send(ServerMessage::SendMessage(
+                                MessageFactory::build_add_thing_i_hate(item),
+                            ));
+                        }
+                    }
                     ClientOperation::ExcludedSearchPhrases(phrases) => {
                         if let Ok(mut ctx) = client_context.write_safe() {
                             ctx.set_excluded_search_phrases(phrases);