feat(navigation): Enhance navigation links and add legacy route redirects

- Updated navigation links in `init_db.py` to include href overrides and parent slugs for profitability, opex, and capex planners.
- Modified `NavigationService` to handle child links and href overrides, ensuring proper routing when context is missing.
- Adjusted scenario detail and list templates to use new route names for opex and capex forms, with legacy fallbacks.
- Introduced integration tests for legacy calculation routes to ensure proper redirection and error handling.
- Added tests for navigation sidebar to validate role-based access and link visibility.
- Enhanced navigation sidebar tests to include calculation links and contextual URLs based on project and scenario IDs.

tests/integration/test_navigation_sidebar.py

@@ -0,0 +1,146 @@
+"""Integration coverage for the /navigation/sidebar endpoint.
+
+These tests validate role-based filtering, ordering, and disabled-link handling
+through the full FastAPI stack so future changes keep navigation behaviour under
+explicit test coverage.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from typing import Any, Mapping
+
+import pytest
+from fastapi.testclient import TestClient
+
+from models.navigation import NavigationGroup, NavigationLink
+from services.unit_of_work import UnitOfWork
+
+
+@pytest.fixture()
+def seed_navigation(unit_of_work_factory: Callable[[], UnitOfWork]) -> Callable[[], None]:
+    def _seed() -> None:
+        with unit_of_work_factory() as uow:
+            repo = uow.navigation
+            assert repo is not None
+
+            workspace = repo.add_group(
+                NavigationGroup(
+                    slug="workspace",
+                    label="Workspace",
+                    sort_order=10,
+                )
+            )
+            insights = repo.add_group(
+                NavigationGroup(
+                    slug="insights",
+                    label="Insights",
+                    sort_order=20,
+                )
+            )
+
+            repo.add_link(
+                NavigationLink(
+                    group_id=workspace.id,
+                    slug="projects",
+                    label="Projects",
+                    href_override="/projects",
+                    sort_order=5,
+                    required_roles=[],
+                )
+            )
+            repo.add_link(
+                NavigationLink(
+                    group_id=workspace.id,
+                    slug="admin-tools",
+                    label="Admin Tools",
+                    href_override="/admin/tools",
+                    sort_order=10,
+                    required_roles=["admin"],
+                )
+            )
+            repo.add_link(
+                NavigationLink(
+                    group_id=workspace.id,
+                    slug="disabled-link",
+                    label="Hidden",
+                    href_override="/hidden",
+                    sort_order=15,
+                    required_roles=[],
+                    is_enabled=False,
+                )
+            )
+            repo.add_link(
+                NavigationLink(
+                    group_id=insights.id,
+                    slug="reports",
+                    label="Reports",
+                    href_override="/reports",
+                    sort_order=1,
+                    required_roles=[],
+                )
+            )
+
+    return _seed
+
+
+def _link_labels(group_json: Mapping[str, Any]) -> list[str]:
+    return [link["label"] for link in group_json["links"]]
+
+
+def test_admin_session_receives_all_enabled_links(
+    client: TestClient,
+    seed_navigation: Callable[[], None],
+) -> None:
+    seed_navigation()
+
+    response = client.get("/navigation/sidebar")
+    assert response.status_code == 200
+    payload = response.json()
+
+    assert [group["label"] for group in payload["groups"]] == [
+        "Workspace",
+        "Insights",
+    ]
+    workspace, insights = payload["groups"]
+    assert _link_labels(workspace) == ["Projects", "Admin Tools"]
+    assert _link_labels(insights) == ["Reports"]
+    assert payload["roles"] == ["admin"]
+
+
+def test_viewer_session_filters_admin_only_links(
+    client: TestClient,
+    seed_navigation: Callable[[], None],
+    test_user_headers: Callable[[str | None], dict[str, str]],
+) -> None:
+    seed_navigation()
+
+    response = client.get(
+        "/navigation/sidebar",
+        headers=test_user_headers("viewer"),
+    )
+    assert response.status_code == 200
+    payload = response.json()
+
+    assert [group["label"] for group in payload["groups"]] == [
+        "Workspace",
+        "Insights",
+    ]
+    workspace, insights = payload["groups"]
+    assert _link_labels(workspace) == ["Projects"]
+    assert _link_labels(insights) == ["Reports"]
+    assert payload["roles"] == ["viewer"]
+
+
+def test_anonymous_access_is_rejected(
+    client: TestClient,
+    seed_navigation: Callable[[], None],
+    test_user_headers: Callable[[str | None], dict[str, str]],
+) -> None:
+    seed_navigation()
+
+    response = client.get(
+        "/navigation/sidebar",
+        headers=test_user_headers("anonymous"),
+    )
+    assert response.status_code == 401