fix(meeting): pass device IDs from components and use exact media constraints

[akulakum]

COMPLETES #https://jira-eng-gpk2.cisco.com/jira/browse/SPARK-824300

Vidcast demo link: https://app.vidcast.io/share/f9ab47df-fd36-4380-8879-d6f23054a3b3

This pull request addresses

Meetings Widget Settings → Audio/Video device selection stopped applying the chosen microphone, speaker, or camera after @webex/sdk-component-adapter@1.113.0 shipped with PR #346.

Customer environment: @webex/widgets ^1.28.2, @webex/components 1.277.1, @webex/sdk-component-adapter 1.113.0, Chrome on macOS.

Root cause: PR #346 refactored meeting control action() methods to read device IDs from a context object (e.g. { meetingID, microphoneId }). However, @webex/components@1.277.1 still invokes device controls as:

control.action({ meetingID }, deviceId)

The device ID is passed as the second argument, not inside the context object. The adapter ignored the second argument, so microphoneId / speakerId / cameraId was undefined and switchMicrophone() never received the selected hardware ID.

Two additional issues made switching unreliable even when partially fixed:

1. Chrome media constraints: getUserMedia({ deviceId: id }) (non-exact) silently falls back to the built-in device when a preview stream is already active. { exact: deviceId } is required for reliable switching.
2. RxJS anti-pattern: getStream() used new Observable(async (subscriber) => …), causing UnsubscriptionError when stopping preview streams during rapid device changes.

by making the following changes

1. Device switch controls — accept 2nd argument from @webex/components

Files: SwitchMicrophoneControl.js, SwitchSpeakerControl.js, SwitchCameraControl.js

async action(context, deviceId) {
  const { meetingID } = context;
  const microphoneId = context.microphoneId != null ? context.microphoneId : deviceId;
  await this.adapter.switchMicrophone(meetingID, microphoneId);
}

Backward-compatible: supports PR #346 context-object shape and the two-argument call pattern used by @webex/components today.

2. Exact media constraints for Chrome

File: MeetingsSDKAdapter.js — switchMicrophone(), switchCamera()

deviceId: microphoneID === 'default' ? 'default' : { exact: microphoneID }

3. Fix getStream() Observable teardown

File: MeetingsSDKAdapter.js — getStream()

• Replaced async Observable subscriber with sync subscriber + async IIFE
• Added clearTimeout(askingTimeout) in teardown to prevent errors during device switch

4. Unit tests

• Tests for action({ meetingID }, deviceId) contract on all three switch controls
• Tests asserting { exact: deviceId } and plain 'default' constraint behavior in MeetingsSDKAdapter.test.js

Change Type

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Tooling change
• Internal code refactor

The following scenarios were tested

• The testing is done with the amplify link
  < ENUMERATE TESTS PERFORMED, WHETHER MANUAL OR AUTOMATED >

The GAI Coding Policy And Copyright Annotation Best Practices

• GAI was not used (or, no additional notation is required)
• Code was generated entirely by GAI
• GAI was used to create a draft that was subsequently customized or modified
• Coder created a draft manually that was non-substantively modified by GAI (e.g., refactoring was performed by GAI on manually written code)
• Tool used for AI assistance (GitHub Copilot / Other - specify)
  • Github Copilot
  • Other - Please Specify
• This PR is related to
  • Feature
  • Defect fix
  • Tech Debt
  • Automation

Checklist before merging

• I have not skipped any automated checks
• All existing and new tests passed
• I have updated the testing document

---