fix(daemon): reconnect after the server session drops

A long-running daemon that lost its TCP connection to the server reported
session_loss "disconnected" and answered every command from the dead session
until a manual restart. Two causes:

- the daemon owned one session for its lifetime with no reconnect at all; and
- the lib's ServerActor queued a Login sent while disconnected instead of
  dialing, so even asking it to log in again never re-established a connection.

Reconnect on a dedicated thread with 1s-60s capped backoff, only for a dropped
connection to a session this process owns (never a displaced or borrowed one,
which would start a login war or fight another daemon). Let a Login through the
disconnected guard so a parked actor dials again, and bound that dial with
connect_timeout so a blackholed route cannot park the actor thread. Reset the
message reader, the queued backlog and the login verdict on disconnect so a
partial frame or stale Some(false) cannot wedge the reconnected session.
Announce the drop once per outage and re-join rooms and re-watch users on
recovery; the daemon main loop is back to save-and-stop so `daemon stop` stays
responsive during an outage. Update the session_loss event summary, which no
longer means the session is gone for good.

soulseek-rs/src/api.rs

@@ -60,6 +60,9 @@ pub trait SessionApi: Send + Sync {
     }
     fn listen_port(&self) -> Option<u16>;
     fn session_loss(&self) -> Option<SessionLoss>;
+    fn relogin(&self) -> Result<bool> {
+        Err(soulseek_rs::SoulseekRs::NotConnected)
+    }
 
     /// Search and wait out the window. Every implementation is
     /// `search_with_cancel` with nothing to cancel on.
@@ -191,6 +194,10 @@ impl SessionApi for Client {
         Self::session_loss(self)
     }
 
+    fn relogin(&self) -> Result<bool> {
+        Self::login(self)
+    }
+
     fn search_with_cancel(
         &self,
         query: &str,