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/nodeHelp.spec.ts

@@ -12,7 +12,7 @@ async function selectNodeWithPan(comfyPage: ComfyPage, nodeRef: NodeReference) {
   const nodePos = await nodeRef.getPosition()
 
   await comfyPage.page.evaluate((pos) => {
-    const app = window['app']!
+    const app = window.app!
     const canvas = app.canvas
     canvas.ds.offset[0] = -pos.x + canvas.canvas.width / 2
     canvas.ds.offset[1] = -pos.y + canvas.canvas.height / 2 + 100
@@ -356,7 +356,7 @@ This is documentation for a custom node.
 
       // Find and select a custom/group node
       const nodeRefs = await comfyPage.page.evaluate(() => {
-        return window['app']!.graph!.nodes.map((n) => n.id)
+        return window.app!.graph!.nodes.map((n) => n.id)
       })
       if (nodeRefs.length > 0) {
         const firstNode = await comfyPage.nodeOps.getNodeRefById(nodeRefs[0])