Changeset: Add unit tests for maintenance-worker-factory

## Description
Changeset to document the addition of unit tests for maintenance-worker-factory.

## Changes
- Added comprehensive unit tests achieving 100% code coverage
- Tests verify MaintenanceWorker instantiation and dependency wiring

## Impact
- Increases test coverage from 0% to 100% (11/11 statements)
- All tests passing

## Type
- Test coverage improvement with changeset documentation