Add Solarium title transition

[vistar941]

Summary

• Add a Solarium-style navigation title transition for string-based titles.
• Use platform-aware title typography with blur, vertical offset, and spring animations.
• Allow the title animation environment value to be optional so the default transition can choose its own animation.
• Refresh the example layout to demonstrate the updated behavior.
• Add a second demo GIF and show both previews in the English and Japanese READMEs.
• Add GitHub Actions builds for iOS Simulator, Mac Catalyst, and macOS using the default Xcode on macos-latest.

Impact

String-based scrollAwareTitle calls adopt the new transition on supported iOS versions, while custom title views retain the existing behavior. Consumers can still override the animation with scrollAwareTitleAnimation(_:).

Validation

• swift test
• xcodebuild for generic/platform=iOS Simulator
• xcodebuild for generic/platform=macOS,variant=Mac Catalyst
• xcodebuild for platform=macOS