feat: add bouncer control commands via /msg *bouncer

Users can now inspect bouncer state and manage it from their IRC client
by sending PRIVMSG to *bouncer (or bouncer). Supported commands:
HELP, STATUS, INFO, UPTIME, NETWORKS, CREDS. Responses arrive as
NOTICE messages. All commands are case-insensitive.

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

docs/USAGE.md

@@ -196,6 +196,42 @@ autojoin = true            # auto-join channels on ready (default: true)
 password = ""              # IRC server password (optional, for PASS command)
 ```
 
+## Bouncer Commands
+
+Send a PRIVMSG to `*bouncer` (or `bouncer`) from your IRC client to inspect
+and control the bouncer. All commands are case-insensitive.
+
+```
+/msg *bouncer HELP
+/msg *bouncer STATUS
+/msg *bouncer INFO libera
+/msg *bouncer UPTIME
+/msg *bouncer NETWORKS
+/msg *bouncer CREDS
+/msg *bouncer CREDS libera
+```
+
+| Command | Description |
+|---------|-------------|
+| `HELP` | List available commands |
+| `STATUS` | Overview: state, nick, host per network |
+| `INFO <network>` | Detailed info for one network (state, server, channels, creds) |
+| `UPTIME` | Bouncer uptime since process start |
+| `NETWORKS` | List all configured networks with state |
+| `CREDS [network]` | NickServ credential status (all or per-network) |
+
+Responses arrive as NOTICE messages from `*bouncer`.
+
+### Example Output
+
+```
+[STATUS]
+  libera     ready  fabesune       user/fabesune
+  oftc       ready  ceraty         cloaked.user
+  hackint    connecting (attempt 3)
+  quakenet   ready  spetyo         --
+```
+
 ## Stopping
 
 Press `Ctrl+C` or send `SIGTERM`. The bouncer shuts down gracefully, closing