feat: stealth connect with random identity and probation window

Register with a fully random nick, user, and realname (no fixed
pattern) to avoid fingerprinting. Enter a 15s probation period
after registration -- if the server k-lines, reconnect with a
fresh identity. Only after surviving probation: switch to the
configured nick and join channels.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

config/bouncer.example.toml

@@ -11,13 +11,15 @@ replay_on_connect = true
 host = "127.0.0.1"
 port = 1080
 
+# Registration uses a random nick and generic ident/realname.
+# After surviving the probation window (no k-line), the bouncer
+# switches to your configured nick and joins channels.
+
 [networks.libera]
 host = "irc.libera.chat"
 port = 6697
 tls = true
 nick = "mynick"
-user = "mynick"
-realname = "bouncer user"
 channels = ["#test"]
 autojoin = true