test(browser): refactor browser tests for reliability and maintainability (#8510)

## Summary

Major refactoring of browser tests to improve reliability,
maintainability, and type safety.

## Changes

### Test Infrastructure Decomposition
- Decomposed `ComfyPage.ts` (~1000 lines) into focused helpers:
- `CanvasHelper`, `DebugHelper`, `SubgraphHelper`,
`NodeOperationsHelper`
- `SettingsHelper`, `WorkflowHelper`, `ClipboardHelper`,
`KeyboardHelper`
- Created `ContextMenu` page object, `BaseDialog` base class, and
`BottomPanel` page object
- Extracted `DefaultGraphPositions` constants

### Locator Stability
- Added `data-testid` attributes to Vue components (sidebar, dialogs,
node library)
- Created centralized `selectors.ts` with test ID constants
- Replaced fragile CSS selectors (`.nth()`, `:nth-child()`) with
`getByTestId`/`getByRole`

### Performance & Reliability
- Removed `setTimeout` anti-patterns (replaced with `waitForFunction`)
- Replaced `waitForTimeout` with retrying assertions
- Replaced hardcoded coordinates with computed `NodeReference` positions
- Enforced LF line endings for all text files

### Type Safety
- Enabled `no-explicit-any` lint rule for browser_tests via oxlint
- Purged `as any` casts from browser_tests
- Added Window type augmentation for standardized window access
- Added proper type annotations throughout

### Bug Fixes
- Restored `ExtensionManager` API contract
- Removed test-only settings from production schema
- Fixed flaky selectors and missing test setup

## Testing
- All browser tests pass
- Typecheck passes


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Tests**
* Overhauled browser E2E test infrastructure with many new
helpers/fixtures, updated test APIs, and CI test container image bumped
for consistency.

* **Chores**
* Standardized line endings and applied stricter lint rules for browser
tests; workspace dependency version updated.

* **Documentation**
* Updated Playwright and TypeScript testing guidance and test-run
commands.

* **UI**
* Added stable data-testids to multiple components to improve
testability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: github-actions <github-actions@github.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

browser_tests/tests/vueNodes/groups/groups.spec.ts

@@ -7,8 +7,8 @@ const CREATE_GROUP_HOTKEY = 'Control+g'
 
 test.describe('Vue Node Groups', { tag: '@screenshot' }, () => {
   test.beforeEach(async ({ comfyPage }) => {
-    await comfyPage.setSetting('Comfy.VueNodes.Enabled', true)
-    await comfyPage.setSetting('Comfy.Minimap.ShowGroups', true)
+    await comfyPage.settings.setSetting('Comfy.VueNodes.Enabled', true)
+    await comfyPage.settings.setSetting('Comfy.Minimap.ShowGroups', true)
     await comfyPage.vueNodes.waitForNodes()
   })
 
@@ -24,9 +24,9 @@ test.describe('Vue Node Groups', { tag: '@screenshot' }, () => {
 
   test('should allow fitting group to contents', async ({ comfyPage }) => {
     await comfyPage.setup()
-    await comfyPage.loadWorkflow('groups/oversized_group')
-    await comfyPage.ctrlA()
-    await comfyPage.executeCommand('Comfy.Graph.FitGroupToContents')
+    await comfyPage.workflow.loadWorkflow('groups/oversized_group')
+    await comfyPage.keyboard.selectAll()
+    await comfyPage.command.executeCommand('Comfy.Graph.FitGroupToContents')
     await comfyPage.nextFrame()
     await expect(comfyPage.canvas).toHaveScreenshot(
       'vue-groups-fit-to-contents.png'
@@ -36,18 +36,20 @@ test.describe('Vue Node Groups', { tag: '@screenshot' }, () => {
   test('should move nested groups together when dragging outer group', async ({
     comfyPage
   }) => {
-    await comfyPage.loadWorkflow('groups/nested-groups-1-inner-node')
+    await comfyPage.workflow.loadWorkflow('groups/nested-groups-1-inner-node')
 
     // Get initial positions with null guards
-    const outerInitial = await comfyPage.getGroupPosition('Outer Group')
-    const innerInitial = await comfyPage.getGroupPosition('Inner Group')
+    const outerInitial =
+      await comfyPage.canvasOps.getGroupPosition('Outer Group')
+    const innerInitial =
+      await comfyPage.canvasOps.getGroupPosition('Inner Group')
 
     const initialOffsetX = innerInitial.x - outerInitial.x
     const initialOffsetY = innerInitial.y - outerInitial.y
 
     // Drag the outer group
     const dragDelta = { x: 100, y: 80 }
-    await comfyPage.dragGroup({
+    await comfyPage.canvasOps.dragGroup({
       name: 'Outer Group',
       deltaX: dragDelta.x,
       deltaY: dragDelta.y
@@ -55,8 +57,10 @@ test.describe('Vue Node Groups', { tag: '@screenshot' }, () => {
 
     // Use retrying assertion to wait for positions to update
     await expect(async () => {
-      const outerFinal = await comfyPage.getGroupPosition('Outer Group')
-      const innerFinal = await comfyPage.getGroupPosition('Inner Group')
+      const outerFinal =
+        await comfyPage.canvasOps.getGroupPosition('Outer Group')
+      const innerFinal =
+        await comfyPage.canvasOps.getGroupPosition('Inner Group')
 
       const finalOffsetX = innerFinal.x - outerFinal.x
       const finalOffsetY = innerFinal.y - outerFinal.y