fix(CORE-001D3A): accept decimal boundary inputs

app/services/alerts.py

@@ -7,9 +7,9 @@ from decimal import Decimal
 from typing import Mapping
 
 from app.domain.portfolio_math import build_alert_context
-from app.domain.units import decimal_from_float
 from app.models.alerts import AlertEvent, AlertHistoryRepository, AlertStatus
 from app.models.portfolio import PortfolioConfig
+from app.services.boundary_values import boundary_decimal
 
 
 @dataclass(frozen=True, slots=True)
@@ -22,48 +22,25 @@ class AlertEvaluationInput:
     email_alerts_enabled: bool
 
 
-def _decimal_from_boundary_value(value: object, *, field_name: str, default: float = 0.0) -> Decimal:
-    if value is None:
-        return decimal_from_float(float(default))
-    if isinstance(value, bool):
-        raise TypeError(f"{field_name} must be numeric, got bool")
-    if isinstance(value, int):
-        parsed = float(value)
-    elif isinstance(value, float):
-        parsed = value
-    elif isinstance(value, str):
-        stripped = value.strip()
-        if not stripped:
-            parsed = float(default)
-        else:
-            try:
-                parsed = float(stripped)
-            except ValueError as exc:
-                raise ValueError(f"{field_name} must be numeric, got {value!r}") from exc
-    else:
-        raise TypeError(f"{field_name} must be numeric, got {type(value)!r}")
-    return decimal_from_float(float(parsed))
-
-
 def _normalize_alert_evaluation_input(
     config: PortfolioConfig,
     portfolio: Mapping[str, object],
 ) -> AlertEvaluationInput:
     return AlertEvaluationInput(
-        ltv_ratio=_decimal_from_boundary_value(
-            portfolio.get("ltv_ratio", 0.0),
+        ltv_ratio=boundary_decimal(
+            portfolio.get("ltv_ratio"),
             field_name="portfolio.ltv_ratio",
         ),
-        spot_price=_decimal_from_boundary_value(
-            portfolio.get("spot_price", 0.0),
+        spot_price=boundary_decimal(
+            portfolio.get("spot_price"),
             field_name="portfolio.spot_price",
         ),
         updated_at=str(portfolio.get("quote_updated_at", "")),
-        warning_threshold=_decimal_from_boundary_value(
+        warning_threshold=boundary_decimal(
             config.ltv_warning,
             field_name="config.ltv_warning",
         ),
-        critical_threshold=_decimal_from_boundary_value(
+        critical_threshold=boundary_decimal(
             config.margin_threshold,
             field_name="config.margin_threshold",
         ),