feat: Add application-level settings for CSS color management

- Introduced a new table `application_setting` to store configurable application options.
- Implemented functions to manage CSS color settings, including loading, updating, and reading environment overrides.
- Added a new settings view to render and manage theme colors.
- Updated UI to include a settings page with theme color management and environment overrides display.
- Enhanced CSS styles for the settings page and sidebar navigation.
- Created unit and end-to-end tests for the new settings functionality and CSS management.

main.py

@@ -16,6 +16,7 @@ from routes.reporting import router as reporting_router
 from routes.currencies import router as currencies_router
 from routes.simulations import router as simulations_router
 from routes.maintenance import router as maintenance_router
+from routes.settings import router as settings_router
 
 # Initialize database schema
 Base.metadata.create_all(bind=engine)
@@ -43,4 +44,5 @@ app.include_router(equipment_router)
 app.include_router(maintenance_router)
 app.include_router(reporting_router)
 app.include_router(currencies_router)
+app.include_router(settings_router)
 app.include_router(ui_router)