Add tests documenting the bug where inline TaskNote widgets in Reading View
don't refresh after property updates. The markdown file updates correctly,
but the widget display remains stale until the file is closed and reopened.
Tests cover:
- Property updates (scheduled date) not refreshing inline widget display
- Status toggle changes not reflected visually
- Multiple instances of same task not refreshing together
- Contrast with Live Preview which does refresh correctly
Root cause: ReadingModeTaskLinkProcessor is a one-time post-processor with
no EVENT_TASK_UPDATED listeners, unlike TaskLinkOverlay.ts (Live Preview).
