feat(discord): add Discord channel support

- Implement Discord channel functionality with websocket integration.
- Update configuration schema to include Discord settings.
- Enhance README with setup instructions for Discord integration.
- Modify channel manager to initialize Discord channel if enabled.
- Update CLI status command to display Discord channel status.

nanobot/cli/commands.py

@@ -362,6 +362,20 @@ def channels_status():
         "✓" if wa.enabled else "✗",
         wa.bridge_url
     )
+
+    tg = config.channels.telegram
+    table.add_row(
+        "Telegram",
+        "✓" if tg.enabled else "✗",
+        "polling"
+    )
+
+    dc = config.channels.discord
+    table.add_row(
+        "Discord",
+        "✓" if dc.enabled else "✗",
+        dc.gateway_url
+    )
     
     console.print(table)