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/graph.spec.ts

@@ -13,7 +13,7 @@ test.describe('Graph', { tag: ['@smoke', '@canvas'] }, () => {
     await comfyPage.workflow.loadWorkflow('inputs/input_order_swap')
     expect(
       await comfyPage.page.evaluate(() => {
-        return window['app'].graph.links.get(1)?.target_slot
+        return window.app.graph.links.get(1)?.target_slot
       })
     ).toBe(1)
   })