feat(CORE-001D): close remaining boundary cleanup slices

app/services/backtesting/input_normalization.py

@@ -0,0 +1,51 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from app.services.boundary_values import boundary_decimal
+
+
+@dataclass(frozen=True, slots=True)
+class NormalizedHistoricalScenarioInputs:
+    underlying_units: float
+    loan_amount: float
+    margin_call_ltv: float
+    currency: str = "USD"
+    cash_balance: float = 0.0
+    financing_rate: float = 0.0
+
+
+def normalize_historical_scenario_inputs(
+    *,
+    underlying_units: object,
+    loan_amount: object,
+    margin_call_ltv: object,
+    currency: object = "USD",
+    cash_balance: object = 0.0,
+    financing_rate: object = 0.0,
+) -> NormalizedHistoricalScenarioInputs:
+    normalized_currency = str(currency).strip().upper()
+    if not normalized_currency:
+        raise ValueError("Currency is required")
+
+    units = float(boundary_decimal(underlying_units, field_name="underlying_units"))
+    normalized_loan_amount = float(boundary_decimal(loan_amount, field_name="loan_amount"))
+    ltv = float(boundary_decimal(margin_call_ltv, field_name="margin_call_ltv"))
+    normalized_cash_balance = float(boundary_decimal(cash_balance, field_name="cash_balance"))
+    normalized_financing_rate = float(boundary_decimal(financing_rate, field_name="financing_rate"))
+
+    if units <= 0:
+        raise ValueError("Underlying units must be positive")
+    if normalized_loan_amount < 0:
+        raise ValueError("Loan amount must be non-negative")
+    if not 0 < ltv < 1:
+        raise ValueError("Margin call LTV must be between 0 and 1")
+
+    return NormalizedHistoricalScenarioInputs(
+        underlying_units=units,
+        loan_amount=normalized_loan_amount,
+        margin_call_ltv=ltv,
+        currency=normalized_currency,
+        cash_balance=normalized_cash_balance,
+        financing_rate=normalized_financing_rate,
+    )