[Feature Request] Togglable autoLeave in config.json

[elch01]

Describe the problem

Description

Currently, when Sable launches Element Call, it hardcodes call URL parameters in src/app/plugins/call/CallEmbed.ts.
There is no mechanism to pass Element Call configuration options (like autoLeaveWhenOthersLeft) from the admin configuration.

Reasoning

I want to disable the automatic call termination when all other participants leave a call.

This behavior is configured in Element Call via the autoLeave URL parameter, which defaults to true for DM-style calls.
However, Sable never passes this parameter, so im guessing default is set to true for any calls.

Technical Details

Relevant Code:

• Sable: src/app/plugins/call/CallEmbed.ts (lines 78-93) constructs the widget URL
• SableCall: src/UrlParams.ts (line 504) reads the autoLeave parameter
• SableCall: src/state/CallViewModel/CallNotificationLifecycle.ts (lines 116-124) uses the autoLeaveWhenOthersLeft option

What's Missing:
Sable needs to:

1. Read call configuration from config.json
2. Pass these options as URL parameters when launching Element Call

Suggested Solution:

Add a new optional callOptions section to config.json:

{
  "callOptions": {
    "autoLeaveWhenOthersLeft": false
  }
}

Describe the solution you'd like

In src/app/plugins/call/CallEmbed.ts

const callConfig = getCallConfig();
const params = new URLSearchParams({
  widgetId,
  parentUrl: clientOrigin,
  baseUrl: mx.baseUrl,
  roomId: room.roomId,
  userId,
  deviceId,
  intent,
  skipLobby: 'true',
  confineToRoom: 'true',
  appPrompt: 'false',
  perParticipantE2EE: room.hasEncryptionStateEvent().toString(),
  lang: 'en-EN',
  theme: themeKind,
  
  // Something like this
  ...(callConfig.autoLeaveWhenOthersLeft !== undefined && {
    autoLeave: callConfig.autoLeaveWhenOthersLeft.toString()
  }),
});

Alternatives considered

No response

Additional context

No response