Add a getBaseUrl mock to audibleServiceMock in audiobooks-browse route tests that returns 'https://www.audible.com'. This ensures tests have a defined base URL for Audible service calls and prevents issues caused by an undefined method during test execution.
Introduces 'series' and 'seriesPart' fields to the Audiobook model and database schema. Updates API routes, file organization, and path template utilities to support series metadata. Enhances chapter merging logic, improves notification backend testing, and expands test coverage for admin and API routes.
Introduced a Vitest-based backend unit testing framework with supporting scripts, helpers, and GitHub Actions integration. Refactored the admin settings page to a modular architecture, splitting monolithic logic into feature-specific tabs and hooks for improved maintainability and testability. Updated documentation to reflect the new testing setup and settings architecture, and added new dependencies for testing utilities.
kikootwo