fix unread count: sent messages don't count as unread

Track outgoing messages separately (own counter) so they appear
in the log but don't inflate unread counts. Reset on recv.

Co-Developed-By: Kent Overstreet <kent.overstreet@linux.dev>

channels/telegram/src/main.rs

@@ -260,9 +260,13 @@ impl channel_server::Server for ChannelServerImpl {
 
             let ts = now() as u64;
             append_history(&format!("{ts} [agent] {message}"));
-            state.borrow_mut().push_message(
-                format!("[agent] {}", message), 0, "telegram.agent"
-            );
+            {
+                let channel = "telegram.agent".to_string();
+                state.borrow_mut().channel_logs
+                    .entry(channel)
+                    .or_insert_with(ChannelLog::new)
+                    .push_own(format!("[agent] {}", message));
+            }
             Ok(())
         })
     }