- Removed `onProgress` callback from `regenerateChapter` and related functions across `TTS`, `EPUB`, and `PDF` contexts to simplify the chapter regeneration API.
- Updated `AudiobookExportModal` to align with the refined regeneration API, including removing granular chapter progress display and adding a hint about TTS caching behavior.
- Introduced `TTSAudiobookChapter` interface and renamed `ContinuationMergeResult` to `TTSSmartMergeResult` and `PageTurnEstimate` to `TTSPageTurnEstimate` for better type consistency and clarity.
- Applied minor styling adjustments to buttons and listbox components in modals for visual consistency.
- Added `'use client'` directive to several client-side components for Next.js 13+ compatibility.
- Updated Dockerfile build command from `pnpm run build` to `pnpm build`.
- Added Playwright tests to verify backend chapter state after regeneration.
- Reduce Playwright worker allocation from 75% to 50% for better resource management
- Disable parallel test execution temporarily to isolate flaky test behavior
- Enhance audio utility to fail fast on user cancellation, preventing unnecessary retries
- Consolidate test-specific utilities within individual test suites for better isolation
- Introduce export functionality test coverage with new export.spec.ts suite
