Feat: dark mode (#3652)

* feat(react/svelte): add dark mode defaults

* refactor(darkmode): minimap, edges, edge labels

* chore(style): edge label color

* feat(colorMode): add colorMode prop light/dark/system

* chore(examples): cleanup

* test(colorMode): add tests

* chore(base.css): add dark base

* chore(examples): cleanup

tests/playwright/e2e/node-toolbar.spec.ts

@@ -1,4 +1,4 @@
-import { test, expect, Locator } from '@playwright/test';
+import { test, expect } from '@playwright/test';
 import { FRAMEWORK } from './constants';
 
 type Position = 'top' | 'right' | 'bottom' | 'left';