Create abstract PhotostreamManager and PhotostreamSegment base classes to enable reusable
timeline-like components. This refactoring extracts common viewport management, scroll
handling, and segment operations from TimelineManager and MonthGroup into reusable
abstractions.
Changes:
- Add PhotostreamManager.svelte.ts with viewport and scroll management
- Add PhotostreamSegment.svelte.ts with segment positioning and intersection logic
- Refactor TimelineManager to extend PhotostreamManager
- Refactor MonthGroup to extend PhotostreamSegment
- Add utility functions for segment identification and date formatting
- Update tests to reflect new inheritance structure
- Extracted asset viewer navigation and action handling logic from Timeline.svelte into a dedicated TimelineAssetViewer component
- Reduces Timeline.svelte complexity by ~150 lines and improves separation of concerns
- No functional changes - purely a refactoring to improve code organization
## Changes
- Created new TimelineAssetViewer.svelte component containing all asset viewer-related logic
- Moved handlePrevious, handleNext, handleRandom, handleClose, handlePreAction, and handleAction methods
- Timeline.svelte now only passes required props to the new component
- Maintained all existing functionality including navigation, asset actions, and stack management
Extracts keyboard shortcuts and related functionality from Timeline component into a dedicated TimelineKeyboardActions component for better separation of concerns and maintainability.
