docs: add IRC commands/plugin setup to README, update WebSocket docs

README was missing IRC command reference, plugin installation/config
guidance, and referenced nonexistent plugin READMEs. The WebSocket
docs in api.md were stale — subscribe message now documents role and
client_id fields, status message now includes the clients array.

Made-with: Cursor

docs/api.md

@@ -412,23 +412,52 @@ WebSocket endpoint for receiving announce broadcasts. Used by IRC bot plugins.
 After connecting, send a subscribe message:
 
 ```json
-{"type": "subscribe", "token": "<NTR_ADMIN_TOKEN>"}
+{
+  "type": "subscribe",
+  "token": "<NTR_ADMIN_TOKEN>",
+  "role": "bot",
+  "client_id": "limnoria"
+}
 ```
 
+| Field | Type | Required | Description |
+|-------|------|----------|-------------|
+| `type` | string | yes | Must be `"subscribe"` |
+| `token` | string | yes | `NTR_ADMIN_TOKEN` value |
+| `role` | string | no | Client role, defaults to `"bot"` |
+| `client_id` | string | no | Identifier for this client (e.g. `"sopel"`, `"limnoria"`) |
+
 Invalid token closes the connection with code `4001`.
 
 **Messages from server**
 
 Announce broadcast:
+
 ```json
 {"type": "announce", "message": "Now Playing: Song #1: Title by Artist - URL"}
 ```
 
 Status update (sent on subscriber connect/disconnect):
+
 ```json
-{"type": "status", "subscribers": 2}
+{
+  "type": "status",
+  "subscribers": 2,
+  "clients": [
+    {
+      "client_id": "limnoria",
+      "remote_addr": "1.2.3.4",
+      "connected_at": "2026-03-12T02:00:00+00:00"
+    }
+  ]
+}
 ```
 
+| Field | Type | Description |
+|-------|------|-------------|
+| `subscribers` | integer | Number of connected bot clients |
+| `clients` | array | List of connected bot clients with their `client_id`, `remote_addr`, and `connected_at` timestamp |
+
 ---
 
 ## Dashboard Configuration