Complete Swift presenter API parity for 0.1.9

[Shinokawa]

Summary

• update the native XCFramework dependency to Erika v0.1.8 and fix ErikaPresenterConfig.video_alpha_mode
• add Swift models and wrappers for subtitle styling/memory fonts, danmaku configuration and multi-track controls, output/upscaler/resource status, and track metadata
• route presenter controls and queries through the direct C ABI instead of the JSON bridge where the C API is available
• add native event/render/audio-only tick APIs while retaining JSON events for extended decoder/audio/error details
• add compatibility tests and update documentation/notices to v0.1.8

Verification

• swiftc -typecheck -strict-concurrency=complete -I /tmp/ce/include Sources/Erika/*.swift -module-name Erika
• swift package dump-package
• git diff --check

The full SwiftPM build was not completed locally because downloading the 560 MB v0.1.8 XCFramework was too slow; CI should perform the final Apple-platform link/test.