feat: enhance database models with metadata and new resource types

models/simulation_parameter.py

@@ -17,6 +17,7 @@ from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.sql import func
 
 from config.database import Base
+from .metadata import ResourceType, StochasticVariable
 
 if TYPE_CHECKING:  # pragma: no cover
     from .scenario import Scenario
@@ -45,6 +46,12 @@ class SimulationParameter(Base):
     distribution: Mapped[DistributionType] = mapped_column(
         SQLEnum(DistributionType), nullable=False
     )
+    variable: Mapped[StochasticVariable | None] = mapped_column(
+        SQLEnum(StochasticVariable), nullable=True
+    )
+    resource_type: Mapped[ResourceType | None] = mapped_column(
+        SQLEnum(ResourceType), nullable=True
+    )
     mean_value: Mapped[float | None] = mapped_column(Numeric(18, 4), nullable=True)
     standard_deviation: Mapped[float | None] = mapped_column(Numeric(18, 4), nullable=True)
     minimum_value: Mapped[float | None] = mapped_column(Numeric(18, 4), nullable=True)