qunit tests: fix runner stalled freezes

[EugeniyKiyashko]

No description provided.

[Copilot]

Pull Request Overview

This pull request addresses critical issues with QUnit test runner stalls and freezes in CI environments by implementing multiple improvements across the test infrastructure.

Key Changes:

• Implemented request queuing and throttling to prevent server overload during parallel test execution
• Added race condition guards to prevent duplicate suite finalization
• Enhanced watchdog monitoring with better logging and configurable timeouts
• Reorganized test constellations by removing viz and ui.htmlEditor categories and redistributing tests to optimize parallel execution

Reviewed Changes

Copilot reviewed 31 out of 40 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
packages/devextreme/testing/runner/Views/Main/RunAll.cshtml	Added finalization queue with concurrency limits (3 concurrent requests), throttled alive notifications (5s), added race condition guards for duplicate finalization, and improved timeout handling with 10s AJAX timeouts
packages/devextreme/testing/runner/Controllers/MainController.cs	Converted NotifySuiteFinalized and NotifyIsAlive to async methods using SemaphoreSlim for thread-safe file I/O, added response writing/flushing, and MAX_WORKERS environment variable support
packages/devextreme/testing/runner/Program.cs	Added aggressive HTTP connection pooling configuration (1000 connections, disabled Nagle) and thread pool tuning (100-1000 threads) to handle high concurrency
packages/devextreme/testing/runner/Tools/UIModelHelper.cs	Removed viz and ui.htmlEditor from known constellations
packages/devextreme/testing/runner/Models/BaseRunViewModel.cs	Added MaxWorkers property for configurable parallel worker count
packages/devextreme/testing/tests/DevExpress.viz.*/__meta.json (12 files)	Moved all viz component tests from viz constellation to ui constellation
packages/devextreme/testing/tests/DevExpress.*.htmlEditor/__meta.json (2 files)	Moved htmlEditor tests from ui.htmlEditor to ui.editors constellation
packages/devextreme/docker-ci.sh	Enhanced watchdog with detailed logging, 30-minute stall detection (6×5min checks), proper PID monitoring, and GitHub Actions mode with 45s startup timeout
packages/devextreme/project.json	Enabled Nx caching for test-env task
e2e/testcafe-devextreme/runner.ts	Changed default cache from true to false, made cache configuration dynamic based on CLI args
e2e/testcafe-devextreme/tests/dataGrid/common/scrolling.ts	Replaced screenshot comparison with functional assertion checking visible rows count, added 100ms load delay simulation
e2e/testcafe-devextreme/tests/dataGrid/common/keyboardNavigation/keyboardNavigation.functional.ts	Marked test as unstable with .meta({ unstable: true })
e2e/testcafe-devextreme/tests/dataGrid/common/filterRow/filterRow.ts	Removed .disablePageReloads fixture configuration and after hook with page reload
apps/demos/utils/visual-tests/testcafe-runner.ts	Removed cache configuration from createTestCafe call and unused THEME import
.github/workflows/qunit_tests.yml	Reduced timeout from 60 to 20 minutes, removed constellation splits (e.g., ui.scheduler(1/2) → ui.scheduler), added MAX_WORKERS environment variable support with values for specific constellations
.github/workflows/testcafe_tests.yml	Split dataGrid tests into 4 parts instead of 3, enabled caching for dataGrid tests, commented out Chrome setup step, changed artifact upload conditions from failure() to always()
.github/workflows/demos_visual_tests.yml	Increased concurrency limits (React: 3→4, Angular: 2→3, other: 2→3)
.github/copilot-instructions.md	Updated QUnit workflow file reference and timeout documentation
.github/actions/run-qunit-tests/action.yml	Added maxWorkers input parameter, commented out Chrome/Node setup steps, changed RawLog artifact upload from failure() to always(), added MAX_WORKERS environment variable

[Copilot]

[nitpick] The hardcoded value 6 for stall threshold should be defined as a constant at the top of the function for better maintainability. This would make it easier to adjust the timeout threshold (currently 30 minutes = 6 checks × 5 min) without searching through the code.