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/opex_snapshot.py

@@ -0,0 +1,123 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import TYPE_CHECKING
+
+from sqlalchemy import JSON, Boolean, DateTime, ForeignKey, Integer, Numeric, String
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.sql import func
+
+from config.database import Base
+
+if TYPE_CHECKING:  # pragma: no cover
+    from .project import Project
+    from .scenario import Scenario
+    from .user import User
+
+
+class ProjectOpexSnapshot(Base):
+    """Snapshot of recurring opex metrics at the project level."""
+
+    __tablename__ = "project_opex_snapshots"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    project_id: Mapped[int] = mapped_column(
+        ForeignKey("projects.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_by_id: Mapped[int | None] = mapped_column(
+        ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    calculation_source: Mapped[str | None] = mapped_column(
+        String(64), nullable=True)
+    calculated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    currency_code: Mapped[str | None] = mapped_column(String(3), nullable=True)
+    overall_annual: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    escalated_total: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    annual_average: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    evaluation_horizon_years: Mapped[int | None] = mapped_column(
+        Integer, nullable=True)
+    escalation_pct: Mapped[float | None] = mapped_column(
+        Numeric(12, 6), nullable=True)
+    apply_escalation: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True)
+    component_count: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    payload: Mapped[dict | None] = mapped_column(JSON, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
+
+    project: Mapped[Project] = relationship(
+        "Project", back_populates="opex_snapshots"
+    )
+    created_by: Mapped[User | None] = relationship("User")
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return (
+            "ProjectOpexSnapshot(id={id!r}, project_id={project_id!r}, overall_annual={overall_annual!r})".format(
+                id=self.id,
+                project_id=self.project_id,
+                overall_annual=self.overall_annual,
+            )
+        )
+
+
+class ScenarioOpexSnapshot(Base):
+    """Snapshot of opex metrics for an individual scenario."""
+
+    __tablename__ = "scenario_opex_snapshots"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    scenario_id: Mapped[int] = mapped_column(
+        ForeignKey("scenarios.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_by_id: Mapped[int | None] = mapped_column(
+        ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    calculation_source: Mapped[str | None] = mapped_column(
+        String(64), nullable=True)
+    calculated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    currency_code: Mapped[str | None] = mapped_column(String(3), nullable=True)
+    overall_annual: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    escalated_total: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    annual_average: Mapped[float | None] = mapped_column(
+        Numeric(18, 2), nullable=True)
+    evaluation_horizon_years: Mapped[int | None] = mapped_column(
+        Integer, nullable=True)
+    escalation_pct: Mapped[float | None] = mapped_column(
+        Numeric(12, 6), nullable=True)
+    apply_escalation: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True)
+    component_count: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    payload: Mapped[dict | None] = mapped_column(JSON, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
+
+    scenario: Mapped[Scenario] = relationship(
+        "Scenario", back_populates="opex_snapshots"
+    )
+    created_by: Mapped[User | None] = relationship("User")
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return (
+            "ScenarioOpexSnapshot(id={id!r}, scenario_id={scenario_id!r}, overall_annual={overall_annual!r})".format(
+                id=self.id,
+                scenario_id=self.scenario_id,
+                overall_annual=self.overall_annual,
+            )
+        )