US-5.6not implemented Calculate personal inflation rate
As a user tracking spending over multiple years I want calculate my personal inflation rate (percentage increase in expenses per year, broken down by category) so that I can see which costs are rising fastest in my own life.
Acceptance Criteria
- The tool compares total expenses (and per-category expenses) year over year.
- Output shows percentage change per category per year.
- Categories with insufficient data are excluded.
No DAG diagram: Not yet implemented — derived metric on the visualisation layer; compares yearly totals from journal data but adds no new DAG nodes.
Demo video coming soon