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/menu.spec.ts

@@ -11,7 +11,7 @@ test.describe('Menu', { tag: '@ui' }, () => {
     const initialChildrenCount = await comfyPage.menu.buttons.count()
 
     await comfyPage.page.evaluate(async () => {
-      window['app'].extensionManager.registerSidebarTab({
+      window.app.extensionManager.registerSidebarTab({
         id: 'search',
         icon: 'pi pi-search',
         title: 'search',
@@ -155,7 +155,7 @@ test.describe('Menu', { tag: '@ui' }, () => {
 
     test('Can catch error when executing command', async ({ comfyPage }) => {
       await comfyPage.page.evaluate(() => {
-        window['app'].registerExtension({
+        window.app.registerExtension({
           name: 'TestExtension1',
           commands: [
             {