feat: Resolve test suite regressions and enhance token tamper detection

feat: Add UI router to application for improved routing
style: Update breadcrumb styles in main.css and remove redundant styles from scenarios.css

tests/conftest.py

@@ -22,6 +22,7 @@ from routes.scenarios import router as scenarios_router
 from routes.imports import router as imports_router
 from routes.exports import router as exports_router
 from routes.reports import router as reports_router
+from routes.ui import router as ui_router
 from services.importers import ImportIngestionService
 from services.unit_of_work import UnitOfWork
 from services.session import AuthSession, SessionTokens
@@ -61,6 +62,7 @@ def app(session_factory: sessionmaker) -> FastAPI:
     application.include_router(imports_router)
     application.include_router(exports_router)
     application.include_router(reports_router)
+    application.include_router(ui_router)
 
     def _override_uow() -> Iterator[UnitOfWork]:
         with UnitOfWork(session_factory=session_factory) as uow: