[Narratively] Voice Channels: let admins and moderators mute everyone in a call at once

Add Mute all for Voice Channel participants with Moderate other Members permission. Narratively runs weekday Daily Quiet Writing Hours and Weekly Tech Office Hours; individual open mics disrupt sessions. Zoom's Mute All is the suggested workaround, moving their most frequent sessions off Heartbeat.

Ticket Info

• Community ID: dfeaf696-48ee-47df-b6a8-5e3402c41db9 (Narratively Community)
• User email(s) for those affected: james@narratively.com (Administrator)

Issue details (include screenshots and steps taken):

Mute all should mute every other participant, including guests and mobile participants, leaving the initiating moderator's mic unchanged. Reuse Moderate other Members; members without that permission must not see the action. Existing individual Mute and Kick must remain unchanged.

Keeping participants muted and joining with mics off are separate requests, outside this issue.

Implementation context on master:

• apps/heartbeat/src/features/voice/VoiceChannelMember.tsx: Mute/Kick menu gated by Permission.Moderate.
• apps/api/src/sockets.ts, voice/muteMember: publishes MuteSelf to one member's PubNub user channel, or the voice channel for guests.
• libs/heartbeat-frontend-data/src/lib/redux-middleware/handleIncomingMessages.ts: MuteSelf calls changeMuteStatus(self, true); recipients can immediately unmute.

Related demand: Featurebase “Mute everyone (for admin)” has 29 votes and has been open since June 2022; Zendesk 51896 also requests bulk mute. Default-off microphones are separately requested in Zendesk 55648 and Featurebase “Mute Mic on Voice Calls by default.”

Repro

Current behavior: on web/desktop, a moderator joins a Voice Channel, hovers over each member in the sidebar, opens the three-dot menu and selects Mute, repeating for each person. Muted members can immediately unmute. Mobile moderators have no Mute or Kick option.

Acceptance: in a call with at least three participants, including one on mobile, a moderator clicks Mute all. Every other participant's mic turns off and displays the muted icon; the moderator's mic remains unchanged. A member without Moderate other Members does not see the action.