feat(daemon): resident session, auth-gated control socket, and event fan-out

The daemon drains the library's destructive take_* accessors once and fans
events out per connection, which is what lets more than one client share a
session. A Unix socket at 0600 is the local transport and its permissions
are the authentication; TCP is opt-in and needs the generated token. Rooms,
transfers, and the conversation are daemon-owned and restored on restart.

soulseek-rs/src/lib.rs

@@ -3,7 +3,11 @@
 
 pub mod api;
 pub mod cli;
+pub mod commands;
 pub mod daemon;
+pub mod directories;
 pub mod models;
 pub mod output;
 pub mod persist;
+pub mod port_mapping;
+pub mod remote;