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>

src/platform/settings/components/SettingDialogContent.vue

@@ -1,5 +1,6 @@
 <template>
   <div
+    data-testid="settings-dialog"
     :class="
       teamWorkspacesEnabled
         ? 'flex h-full w-full overflow-auto flex-col md:flex-row'
@@ -50,10 +51,17 @@
         <template v-else #optiongroup>
           <Divider class="my-0" />
         </template>
-        <!-- Workspace mode: custom workspace item -->
-        <template v-if="teamWorkspacesEnabled" #option="{ option }">
-          <WorkspaceSidebarItem v-if="option.key === 'workspace'" />
-          <span v-else>{{ option.translatedLabel }}</span>
+        <!-- Custom option template with data-testid for stable test selectors -->
+        <template #option="{ option }">
+          <span
+            :data-testid="`settings-tab-${option.key}`"
+            class="settings-tab-option"
+          >
+            <WorkspaceSidebarItem
+              v-if="teamWorkspacesEnabled && option.key === 'workspace'"
+            />
+            <template v-else>{{ option.translatedLabel }}</template>
+          </span>
         </template>
       </Listbox>
     </ScrollPanel>