feat(discord): add set-presence action for bot activity and status

Bridge the agent tools layer to the Discord gateway WebSocket via a new
gateway registry, allowing agents to set the bot's activity and online
status. Supports playing, streaming, listening, watching, custom, and
competing activity types. Custom type uses activityState as the sidebar
text; other types show activityName in the sidebar and activityState in
the flyout. Opt-in via channels.discord.actions.presence (default false).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/discord/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: discord
-description: Use when you need to control Discord from OpenClaw via the discord tool: send messages, react, post or upload stickers, upload emojis, run polls, manage threads/pins/search, create/edit/delete channels and categories, fetch permissions or member/role/channel info, or handle moderation actions in Discord DMs or channels.
+description: Use when you need to control Discord from OpenClaw via the discord tool: send messages, react, post or upload stickers, upload emojis, run polls, manage threads/pins/search, create/edit/delete channels and categories, fetch permissions or member/role/channel info, set bot presence/activity, or handle moderation actions in Discord DMs or channels.
 metadata: {"openclaw":{"emoji":"🎮","requires":{"config":["channels.discord"]}}}
 ---
 
@@ -139,6 +139,7 @@ Use `discord.actions.*` to disable action groups:
 - `roles` (role add/remove, default `false`)
 - `channels` (channel/category create/edit/delete/move, default `false`)
 - `moderation` (timeout/kick/ban, default `false`)
+- `presence` (bot status/activity, default `false`)
 
 ### Read recent messages
 
@@ -432,6 +433,101 @@ Create, edit, delete, and move channels and categories. Enable via `discord.acti
 }
 ```
 
+### Bot presence/activity (disabled by default)
+
+Set the bot's online status and activity. Enable via `discord.actions.presence: true`.
+
+Discord bots can only set `name`, `state`, `type`, and `url` on an activity. Other Activity fields (details, emoji, assets) are accepted by the gateway but silently ignored by Discord for bots.
+
+**How fields render by activity type:**
+
+- **playing, streaming, listening, watching, competing**: `activityName` is shown in the sidebar under the bot's name (e.g. "**with fire**" for type "playing" and name "with fire"). `activityState` is shown in the profile flyout.
+- **custom**: `activityName` is ignored. Only `activityState` is displayed as the status text in the sidebar.
+- **streaming**: `activityUrl` may be displayed or embedded by the client.
+
+**Set playing status:**
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "playing",
+  "activityName": "with fire"
+}
+```
+
+Result in sidebar: "**with fire**". Flyout shows: "Playing: with fire"
+
+**With state (shown in flyout):**
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "playing",
+  "activityName": "My Game",
+  "activityState": "In the lobby"
+}
+```
+
+Result in sidebar: "**My Game**". Flyout shows: "Playing: My Game (newline) In the lobby".
+
+**Set streaming (optional URL, may not render for bots):**
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "streaming",
+  "activityName": "Live coding",
+  "activityUrl": "https://twitch.tv/example"
+}
+```
+
+**Set listening/watching:**
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "listening",
+  "activityName": "Spotify"
+}
+```
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "watching",
+  "activityName": "the logs"
+}
+```
+
+**Set a custom status (text in sidebar):**
+
+```json
+{
+  "action": "setPresence",
+  "activityType": "custom",
+  "activityState": "Vibing"
+}
+```
+
+Result in sidebar: "Vibing". Note: `activityName` is ignored for custom type.
+
+**Set bot status only (no activity/clear status):**
+
+```json
+{
+  "action": "setPresence",
+  "status": "dnd"
+}
+```
+
+**Parameters:**
+
+- `activityType`: `playing`, `streaming`, `listening`, `watching`, `competing`, `custom`
+- `activityName`: text shown in the sidebar for non-custom types (ignored for `custom`)
+- `activityUrl`: Twitch or YouTube URL for streaming type (optional; may not render for bots)
+- `activityState`: for `custom` this is the status text; for other types it shows in the profile flyout
+- `status`: `online` (default), `dnd`, `idle`, `invisible`
+
 ## Discord Writing Style Guide
 
 **Keep it conversational!** Discord is a chat platform, not documentation.