feat: Enhance currency handling and validation across scenarios

- Updated form template to prefill currency input with default value and added help text for clarity.
- Modified integration tests to assert more descriptive error messages for invalid currency codes.
- Introduced new tests for currency normalization and validation in various scenarios, including imports and exports.
- Added comprehensive tests for pricing calculations, ensuring defaults are respected and overrides function correctly.
- Implemented unit tests for pricing settings repository, ensuring CRUD operations and default settings are handled properly.
- Enhanced scenario pricing evaluation tests to validate currency handling and metadata defaults.
- Added simulation tests to ensure Monte Carlo runs are accurate and handle various distribution scenarios.

routes/projects.py

@@ -7,6 +7,7 @@ from fastapi.responses import HTMLResponse, RedirectResponse
 from fastapi.templating import Jinja2Templates
 
 from dependencies import (
+    get_pricing_metadata,
     get_unit_of_work,
     require_any_role,
     require_project_resource,
@@ -15,6 +16,7 @@ from dependencies import (
 from models import MiningOperationType, Project, ScenarioStatus, User
 from schemas.project import ProjectCreate, ProjectRead, ProjectUpdate
 from services.exceptions import EntityConflictError, EntityNotFoundError
+from services.pricing import PricingMetadata
 from services.unit_of_work import UnitOfWork
 
 router = APIRouter(prefix="/projects", tags=["Projects"])
@@ -54,6 +56,7 @@ def create_project(
     payload: ProjectCreate,
     _: User = Depends(require_roles(*MANAGE_ROLES)),
     uow: UnitOfWork = Depends(get_unit_of_work),
+    metadata: PricingMetadata = Depends(get_pricing_metadata),
 ) -> ProjectRead:
     project = Project(**payload.model_dump())
     try:
@@ -62,6 +65,9 @@ def create_project(
         raise HTTPException(
             status_code=status.HTTP_409_CONFLICT, detail=str(exc)
         ) from exc
+    default_settings = uow.ensure_default_pricing_settings(
+        metadata=metadata).settings
+    uow.set_project_pricing_settings(created, default_settings)
     return _to_read_model(created)
 
 
@@ -122,6 +128,7 @@ def create_project_submit(
     operation_type: str = Form(...),
     description: str | None = Form(None),
     uow: UnitOfWork = Depends(get_unit_of_work),
+    metadata: PricingMetadata = Depends(get_pricing_metadata),
 ):
     def _normalise(value: str | None) -> str | None:
         if value is None:
@@ -152,7 +159,7 @@ def create_project_submit(
         description=_normalise(description),
     )
     try:
-        _require_project_repo(uow).create(project)
+        created = _require_project_repo(uow).create(project)
     except EntityConflictError as exc:
         return templates.TemplateResponse(
             request,
@@ -167,6 +174,10 @@ def create_project_submit(
             status_code=status.HTTP_409_CONFLICT,
         )
 
+    default_settings = uow.ensure_default_pricing_settings(
+        metadata=metadata).settings
+    uow.set_project_pricing_settings(created, default_settings)
+
     return RedirectResponse(
         request.url_for("projects.project_list_page"),
         status_code=status.HTTP_303_SEE_OTHER,