ratatui_ruby v0.9.1 released

ratatui_ruby v0.9.1 is out.

This release adds constraint batch constructors and async synchronization
primitives for deterministic testing.

## Added

Constraint now provides batch factory methods matching upstream Ratatui.
Create constraint arrays in a single call instead of mapping individually:

- from_lengths([10, 20, 10])
- from_percentages([25, 50, 25])
- from_mins([5, 10, 5])
- from_maxes([20, 30, 40])
- from_fills([1, 2, 1])
- from_ratios([[1, 4], [2, 4], [1, 4]])

Event::Sync and SyntheticEvents enable deterministic async testing.
When a runtime (Tea, Kit) encounters a Sync event, it waits for all
pending async operations before continuing. Use inject_sync in tests
between async-triggering events and assertions.

Production apps can use Event::Sync too. Push it to SyntheticEvents
when you need to ensure saves complete before quit.

No breaking changes.

Full changelog: https://git.sr.ht/~kerrick/ratatui_ruby/tree/v0.9.1/item/CHANGELOG.md
Gem: https://rubygems.org/gems/ratatui_ruby