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## Summary by CodeRabbit
* **New Features**
* Introduced a Document Summary module, enabling live and cached
document summaries with cloud revalidation.
* Added a feature flag for enabling battery save mode.
* Added explicit pause and resume controls for sync operations,
accessible via UI events and programmatically.
* **Improvements**
* Enhanced sync and indexing logic to support pausing, resuming, and
battery save mode, with improved job prioritization.
* Updated navigation and preview components to use the new document
summary service and improved priority handling.
* Improved logging and state reporting for sync and indexing processes.
* Refined backlink handling with reactive loading states and cloud
revalidation.
* Replaced backlink and link management to use a new dedicated document
links service.
* Enhanced workspace engine to conditionally enable battery save mode
based on feature flags and workspace flavor.
* **Bug Fixes**
* Removed unnecessary debug console logs from various components for
cleaner output.
* **Refactor**
* Replaced battery save mode methods with explicit pause/resume methods
throughout the app and services.
* Modularized and streamlined document summary and sync-related code for
better maintainability.
* Restructured backlink components to improve visibility handling and
data fetching.
* Simplified and improved document backlink data fetching with retry and
loading state management.
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Introduced a battery save mode that can pause background sync and
processing to conserve energy.
* Battery save mode is automatically enabled when the app window loses
focus and disabled when the window regains focus or is interacted with.
* Available in both web and desktop (Electron) versions.
* **Improvements**
* Added user activity detection to optimize background operations for
better battery efficiency.
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