Refactored plugin-iframe tests to be more reliable in CI environment:
- Replaced arbitrary waitForTimeout calls with proper waitFor conditions
- Used Playwright locators instead of page.evaluate() for DOM manipulation
- Added proper state verification using waitForFunction
- Increased timeouts appropriately for CI environment
- Improved error handling for iframe content access
- Made test more resilient to timing variations
These changes make the tests deterministic and reliable across different
environments without relying on fixed wait times.
- Remove all console.log statements from E2E test files
- Replace console.error with throw new Error for proper error handling
- Remove console.warn statements
- Fix unused variable linting errors in plugin tests
