Task: Update Tests and Docs for Runtime Refactoring

Signature Changes

• [x] Update RBS signatures for new Runtime.run signature

• [x] Add with_argv helper to ratatui_ruby test_helper

• [x] Update Tea.run wrapper signature

Test Updates

• [x] Update test_fragment_first_api.rb - change fragment: to positional

• [x] Fix argv/env tests to use with_argv/with_env helpers

• [x] Fix all Command.custom tests to use Ractor-shareable callables

• [ ] Fix test_init_triggers_update_before_first_event - still failing

• [ ] Fix test_fragment_first_api_passes_argv_and_env_to_init - ENV hash comparison issue

• [ ] Update test_snapshots.rb - change all Tea.run calls (15+ occurrences)

• [ ] Update test_fractal_dashboard.rb - change Tea.run calls

• [ ] Update all other test files using Tea.run

• [ ] Add test for fps: parameter

Example Updates

• [ ] Update verify_readme_usage/app.rb

• [ ] Update app_fractal_dashboard Init callables (remove argv/env params)

Current Status

3 failures, 1 error: Making final fixes - test_init_triggers_update_before_first_event - still needs investigation - test_fragment_first_api_passes_argv_and_env_to_init - ENV not being passed correctly - test_cancelled_wait_acknowledges_cancellation - intermittent - test_custom_accepts_block - fixing Command.custom wrapper pattern

Restructuring Command.custom tests to demonstrate automatic shareability handling.