Fix flaky Capybara tests with Chosen.js dropdowns

[mroderick]

Summary

• Fixes two failing feature tests that were timing-dependent when interacting with Chosen.js dropdowns
• Rewrites the select_from_chosen test helper to be more reliable
• All 777 tests now pass consistently

Problem

Two feature tests were failing locally due to race conditions when interacting with Chosen.js select dropdowns:

1. spec/features/member_feedback_spec.rb:60 - Submitting feedback
2. spec/features/admin/manage_workshop_attendances_spec.rb:44 - RSVPing members

The original select_from_chosen helper tried to click the Chosen UI and type text, which was unreliable because:

• Dropdown animations might not be complete
• Elements could be intercepted by other elements
• Timing varied between local and CI environments

Solution

Rewrote select_from_chosen helper to:

• Find the hidden select element and option by text
• Set the value directly via JavaScript
• Trigger Chosen's update events
• Verify the selection was applied

This approach:

• Bypasses UI timing issues entirely
• Is faster and more reliable
• Follows testing best practices for JS-enhanced form elements

Additional improvements:

• Increased Capybara.default_max_wait_time to 5 seconds for better JS test stability
• Added explicit waits for Chosen initialization in tests
• Used the helper consistently across all Chosen dropdown interactions

Test Results

Finished in 2 minutes 46.7 seconds
777 examples, 0 failures

All tests pass with the same seed (63863) that previously caused failures.

Test plan

• Run full test suite locally: bundle exec rspec
• Run with specific seed that previously failed: bundle exec rspec --seed 63863
• Run failing tests individually to verify fixes
• Verify no regressions in other tests