Stabilize E2E tests with cross-browser fixes and improved test patterns

[tjementum]

Summary & Motivation

Stabilize end-to-end tests by fixing cross-browser timing issues and improving test patterns. The test suite now passes consistently across Chromium, Firefox, and WebKit browsers.

Browser-specific fixes:

• Fix OTP typing reliability in Firefox and WebKit by using direct event dispatching with microtask yields between characters, allowing React state updates to propagate before the next keystroke
• Add browser-specific auth state paths to prevent cross-browser test isolation failures when running tests in parallel
• Fix WebKit auth validation race condition in ownerPage fixture by waiting for network idle before checking URL

Revert Rsbuild runtime error overlay:

• Remove the recently added Rsbuild runtime error overlay feature that was causing false positive test failures
• The overlay catches benign ResizeObserver loop completed warnings (especially common in Firefox) and displays a blocking full-screen error
• Rsbuild does not support filtering runtime errors (unlike Rspack), making it impossible to show the overlay for real errors while hiding benign warnings

Code quality improvements:

• Replace useEffect toast anti-pattern with onSuccess callbacks in mutation handlers
• Add pending state text feedback to invite user submit button
• Update frontend rules with toast timing and dirty modal patterns

Test infrastructure:

• Add flaky test tracking skill for systematic E2E failure logging
• Update QA review workflow to run full regression test suite before commit

Checklist

• I have added tests, or done manual regression tests
• I have updated the documentation, if necessary

[linear]

PP-765 Stabilize flaky E2E tests

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud