Messaging · Messages: messages in runs, threads, the unread line and receipts

ChatMessage sets a message under its author's picture, name and clock
time. The next by the same author within five minutes, on the same day,
joins the run: only its words, the time in the gutter on hover.
UnreadDivider marks where unread messages start. MessageThread tells who
replied, how many and when the last came; with a handler it opens on a
press, Enter or Space. ThreadPanel holds the first message, a rule
counting the replies, the replies and a composer, its body scrolling.
ReadReceipt says sending, sent, delivered or read, and who saw it in a
group. MessageReactions and TypingIndicator point to collab and motion.

gpui recolors nothing on hover: text takes its color at layout. The
gutter time rests invisible and turns visible through a group hover.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/messaging/mod.rs

@@ -1,10 +1,16 @@
 mod channels;
 mod header;
+mod messages;
 mod pins;
+mod receipt;
+mod thread;
 
 #[cfg(all(test, feature = "test-support"))]
 mod tests;
 
 pub use channels::{ChannelItem, ChannelList, ChatRow, DirectMessageItem};
 pub use header::ChannelHeader;
+pub use messages::{ChatMessage, UnreadDivider};
 pub use pins::{PinnedMessage, PinnedMessages};
+pub use receipt::{Delivery, ReadReceipt};
+pub use thread::{MessageThread, ThreadPanel};