feat: add scenarios list page with metrics and quick actions

- Introduced a new template for listing scenarios associated with a project.
- Added metrics for total, active, draft, and archived scenarios.
- Implemented quick actions for creating new scenarios and reviewing project overview.
- Enhanced navigation with breadcrumbs for better user experience.

refactor: update Opex and Profitability templates for consistency

- Changed titles and button labels for clarity in Opex and Profitability templates.
- Updated form IDs and action URLs for better alignment with new naming conventions.
- Improved navigation links to include scenario and project overviews.

test: add integration tests for Opex calculations

- Created new tests for Opex calculation HTML and JSON flows.
- Validated successful calculations and ensured correct data persistence.
- Implemented tests for currency mismatch and unsupported frequency scenarios.

test: enhance project and scenario route tests

- Added tests to verify scenario list rendering and calculator shortcuts.
- Ensured scenario detail pages link back to the portfolio correctly.
- Validated project detail pages show associated scenarios accurately.

models/scenario.py

@@ -21,7 +21,7 @@ from services.currency import normalise_currency
 from .enums import ResourceType, ScenarioStatus, sql_enum
 from .profitability_snapshot import ScenarioProfitability
 from .capex_snapshot import ScenarioCapexSnapshot
-from .processing_opex_snapshot import ScenarioProcessingOpexSnapshot
+from .opex_snapshot import ScenarioOpexSnapshot
 
 if TYPE_CHECKING:  # pragma: no cover
     from .financial_input import FinancialInput
@@ -92,11 +92,11 @@ class Scenario(Base):
         order_by=lambda: ScenarioCapexSnapshot.calculated_at.desc(),
         passive_deletes=True,
     )
-    processing_opex_snapshots: Mapped[List["ScenarioProcessingOpexSnapshot"]] = relationship(
-        "ScenarioProcessingOpexSnapshot",
+    opex_snapshots: Mapped[List["ScenarioOpexSnapshot"]] = relationship(
+        "ScenarioOpexSnapshot",
         back_populates="scenario",
         cascade="all, delete-orphan",
-        order_by=lambda: ScenarioProcessingOpexSnapshot.calculated_at.desc(),
+        order_by=lambda: ScenarioOpexSnapshot.calculated_at.desc(),
         passive_deletes=True,
     )
 
@@ -125,9 +125,9 @@ class Scenario(Base):
         return self.capex_snapshots[0]
 
     @property
-    def latest_processing_opex(self) -> "ScenarioProcessingOpexSnapshot | None":
-        """Return the most recent processing opex snapshot for this scenario."""
+    def latest_opex(self) -> "ScenarioOpexSnapshot | None":
+        """Return the most recent opex snapshot for this scenario."""
 
-        if not self.processing_opex_snapshots:
+        if not self.opex_snapshots:
             return None
-        return self.processing_opex_snapshots[0]
+        return self.opex_snapshots[0]