Until now life events were stored but ignored by the engine — pure
metadata. Now they actually move portfolios.
Engine:
- simulator.simulate() takes optional cashflow_adjustments: a (n_years,)
real-GBP array applied each year *after* savings + return but
*before* withdrawal. Positive = inflow, negative = outflow.
- New fire_planner/life_events.py with EventInput dataclass +
events_to_cashflow_array(events, horizon). Handles ranged deltas,
one-time amounts, disabled events, year clipping past horizon,
negative year_start (clipped to 0), and summing multiple events.
API:
- /simulate accepts optional life_events list. Server converts each
to EventInput, builds cashflow_adjustments, passes to simulate().
- Frontend Run-now on scenario detail now fetches the scenario's
life events and includes them in the request — projections finally
reflect "retire at 50, kid born at y3, inheritance at y22".
Tests: 11 events helper + 4 end-to-end engine + 1 API integration =
16 new tests. 188 total (was 172). mypy strict + ruff clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>