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/navigation.py

@@ -0,0 +1,125 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import List, Optional
+
+from sqlalchemy import (
+    Boolean,
+    CheckConstraint,
+    DateTime,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    UniqueConstraint,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.sql import func
+from sqlalchemy.ext.mutable import MutableList
+from sqlalchemy import JSON
+
+from config.database import Base
+
+
+class NavigationGroup(Base):
+    __tablename__ = "navigation_groups"
+    __table_args__ = (
+        UniqueConstraint("slug", name="uq_navigation_groups_slug"),
+        Index("ix_navigation_groups_sort_order", "sort_order"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    slug: Mapped[str] = mapped_column(String(64), nullable=False)
+    label: Mapped[str] = mapped_column(String(128), nullable=False)
+    sort_order: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=100)
+    icon: Mapped[Optional[str]] = mapped_column(String(64))
+    tooltip: Mapped[Optional[str]] = mapped_column(String(255))
+    is_enabled: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=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()
+    )
+
+    links: Mapped[List["NavigationLink"]] = relationship(
+        "NavigationLink",
+        back_populates="group",
+        cascade="all, delete-orphan",
+        order_by="NavigationLink.sort_order",
+    )
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return f"NavigationGroup(id={self.id!r}, slug={self.slug!r})"
+
+
+class NavigationLink(Base):
+    __tablename__ = "navigation_links"
+    __table_args__ = (
+        UniqueConstraint("group_id", "slug",
+                         name="uq_navigation_links_group_slug"),
+        Index("ix_navigation_links_group_sort", "group_id", "sort_order"),
+        Index("ix_navigation_links_parent_sort",
+              "parent_link_id", "sort_order"),
+        CheckConstraint(
+            "(route_name IS NOT NULL) OR (href_override IS NOT NULL)",
+            name="ck_navigation_links_route_or_href",
+        ),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    group_id: Mapped[int] = mapped_column(
+        ForeignKey("navigation_groups.id", ondelete="CASCADE"), nullable=False
+    )
+    parent_link_id: Mapped[Optional[int]] = mapped_column(
+        ForeignKey("navigation_links.id", ondelete="CASCADE")
+    )
+    slug: Mapped[str] = mapped_column(String(64), nullable=False)
+    label: Mapped[str] = mapped_column(String(128), nullable=False)
+    route_name: Mapped[Optional[str]] = mapped_column(String(128))
+    href_override: Mapped[Optional[str]] = mapped_column(String(512))
+    match_prefix: Mapped[Optional[str]] = mapped_column(String(512))
+    sort_order: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=100)
+    icon: Mapped[Optional[str]] = mapped_column(String(64))
+    tooltip: Mapped[Optional[str]] = mapped_column(String(255))
+    required_roles: Mapped[list[str]] = mapped_column(
+        MutableList.as_mutable(JSON), nullable=False, default=list
+    )
+    is_enabled: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True)
+    is_external: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=False)
+    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()
+    )
+
+    group: Mapped[NavigationGroup] = relationship(
+        NavigationGroup,
+        back_populates="links",
+    )
+    parent: Mapped[Optional["NavigationLink"]] = relationship(
+        "NavigationLink",
+        remote_side="NavigationLink.id",
+        back_populates="children",
+    )
+    children: Mapped[List["NavigationLink"]] = relationship(
+        "NavigationLink",
+        back_populates="parent",
+        cascade="all, delete-orphan",
+        order_by="NavigationLink.sort_order",
+    )
+
+    def is_visible_for_roles(self, roles: list[str]) -> bool:
+        if not self.required_roles:
+            return True
+        role_set = set(roles)
+        return any(role in role_set for role in self.required_roles)
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return f"NavigationLink(id={self.id!r}, slug={self.slug!r})"