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/helpers/templates.ts

@@ -6,18 +6,19 @@ import type {
   TemplateInfo,
   WorkflowTemplates
 } from '../../src/platform/workflow/templates/types/template'
+import { TestIds } from '../fixtures/selectors'
 
 export class ComfyTemplates {
   readonly content: Locator
   readonly allTemplateCards: Locator
 
   constructor(readonly page: Page) {
-    this.content = page.getByTestId('template-workflows-content')
+    this.content = page.getByTestId(TestIds.templates.content)
     this.allTemplateCards = page.locator('[data-testid^="template-workflow-"]')
   }
 
-  async waitForMinimumCardCount(count: number) {
-    return await expect(async () => {
+  async expectMinimumCardCount(count: number) {
+    await expect(async () => {
       const cardCount = await this.allTemplateCards.count()
       expect(cardCount).toBeGreaterThanOrEqual(count)
     }).toPass({
@@ -26,14 +27,16 @@ export class ComfyTemplates {
   }
 
   async loadTemplate(id: string) {
-    const templateCard = this.content.getByTestId(`template-workflow-${id}`)
+    const templateCard = this.content.getByTestId(
+      TestIds.templates.workflowCard(id)
+    )
     await templateCard.scrollIntoViewIfNeeded()
     await templateCard.getByRole('img').click()
   }
 
   async getAllTemplates(): Promise<TemplateInfo[]> {
     const templates: WorkflowTemplates[] = await this.page.evaluate(() =>
-      window['app'].api.getCoreWorkflowTemplates()
+      window.app!.api.getCoreWorkflowTemplates()
     )
     return templates.flatMap((t) => t.templates)
   }