test: add Window type augmentation and standardize window access

- Add browser_tests/types/globals.d.ts with Window interface augmentation

- Add types for app, graph, LiteGraph, LGraphBadge and test globals

- Standardize window['prop'] to window.prop across 37 test files

- Update browser_tests/tsconfig.json to include new type definitions

Amp-Thread-ID: https://ampcode.com/threads/T-019c16b3-cc31-70ea-9727-a933cb0ee942
Co-authored-by: Amp <amp@ampcode.com>

browser_tests/tests/graphCanvasMenu.spec.ts

@@ -26,7 +26,7 @@ test.describe('Graph Canvas Menu', { tag: ['@screenshot', '@canvas'] }, () => {
         'canvas-with-hidden-links.png'
       )
       const hiddenLinkRenderMode = await comfyPage.page.evaluate(() => {
-        return window['LiteGraph'].HIDDEN_LINK
+        return window.LiteGraph.HIDDEN_LINK
       })
       expect(await comfyPage.settings.getSetting('Comfy.LinkRenderMode')).toBe(
         hiddenLinkRenderMode