When a source has been updated this cycle, shows the value change from the
previous snapshot in green (increase) or red (decrease).
Fixes#21
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds chevron buttons to navigate between months, similar to Lose It Log view.
The next month button is disabled when already at the current month.
Fixes#20
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
alexandrev-tibco