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/docs/openrpc.json

@@ -2193,7 +2193,7 @@
           "type": "null"
         }
       },
-      "summary": "The server session ended; nothing seen after this means anything.",
+      "summary": "The server session was lost. A disconnected session is reconnected on its own and events resume; a displaced one is terminal. Read daemon.status for the live state.",
       "x-notification": true
     }
   ],