feat(KB-049): add hide done tasks toggle to list view

- Add toggle UI for hiding completed tasks in ListView component
- Implement filtering logic to conditionally render done tasks
- Add comprehensive tests for hide done tasks feature
- Include changeset for the new feature
- Update vitest configs and clean up gitignore coverage entries

.changeset/hide-done-tasks-list-view.md

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+"@dustinbyrne/kb": patch
+---
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+Add ability to hide done tasks in list view. The toggle persists in localStorage and helps declutter the view when many tasks are completed.