refactor: migrate {AccountActivity,BackendWebSocket}Service to @metamask/messenger

[cryptodev-2s]

Explanation

This PR migrates AccountActivityService and BackendWebSocketService to the new @metamask/messenger message bus, as opposed to the one exported from @metamask/base-controller.

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

---

Note

Replace base-controller RestrictedMessenger with @metamask/messenger across services, tests, and exports, with breaking type/constant removals and dependency/config updates.

• Core:
  • Migrate AccountActivityService and BackendWebSocketService to @metamask/messenger (Messenger), replacing RestrictedMessenger from @metamask/base-controller.
  • Update service messenger typedefs (AccountActivityServiceMessenger, BackendWebSocketServiceMessenger) and allowed action/event type aliases (AllowedActions, AllowedEvents).
  • Remove exports of controller-messenger-specific type aliases/constants from index.ts and AccountActivityService.
• Tests:
  • Rework test messengers to use @metamask/messenger with root/child namespaces and delegate; add helpers like getRootMessenger.
  • Adjust publish calls (synchronous) and type plumbing; update mocks/registrations accordingly.
• Config/Deps:
  • Add dependency @metamask/messenger; remove reliance on @metamask/base-controller; update TS references to ../messenger.
  • Update yarn.lock for new dependency.
• Changelog:
  • Document BREAKING changes: adoption of new Messenger and removal of exported controller-messenger-specific types/constants.

^{Written by Cursor Bugbot for commit b7ebc18. This will update automatically on new commits. Configure here.}

[Kriys94]

LGTM :)

[cursor]

Bug: Race Conditions in Test Asynchronous Operations

Removing await from rootMessenger.publish() calls in tests can introduce race conditions. Asynchronous event handlers triggered by the publish might not complete before subsequent assertions, potentially causing test flakiness, even with completeAsyncOperations() called afterward.

Additional Locations (6)

• packages/core-backend/src/AccountActivityService.test.ts#L723-L724
• packages/core-backend/src/AccountActivityService.test.ts#L774-L775
• packages/core-backend/src/AccountActivityService.test.ts#L804-L805
• packages/core-backend/src/AccountActivityService.test.ts#L826-L827
• packages/core-backend/src/AccountActivityService.test.ts#L866-L867
• packages/core-backend/src/AccountActivityService.test.ts#L904-L905