id: CORE-001D3C
title: Historical Scenario Service Input Normalization
status: done
priority: P2
effort: S
depends_on:
  - CORE-001C
  - CORE-001D3A
tags:
  - core
  - decimal
  - backtesting
  - event-comparison
summary: Backtest and event-comparison service entrypoints now normalize historical scenario inputs through a shared named adapter.
completed_notes:
  - Added `normalize_historical_scenario_inputs(...)` in `app/services/backtesting/input_normalization.py`.
  - `BacktestPageService`, `EventComparisonService`, and `EventComparisonPageService` now normalize units/loan/LTV inputs through the shared adapter instead of ad-hoc float checks.
  - The shared adapter now accepts Decimal and numeric-string boundary values while still failing closed on invalid or non-finite inputs.
  - Added focused regression coverage in `tests/test_backtest_ui.py` and `tests/test_event_comparison_ui.py`.
  - Validated with focused pytest coverage, browser-driven checks on local Docker, and `make build`.