feat: Add Swift Package Manager (SPM) Support

[ekasetiawans]

Add Swift Package Manager (SPM) Support

Summary

This pull request adds Swift Package Manager (SPM) support for the iOS implementation of the plugin.

Background

Flutter has introduced support for iOS dependency management through Swift Package Manager, providing an alternative to CocoaPods. As adoption of SPM continues to grow within the Flutter ecosystem, plugin compatibility with SPM becomes increasingly important.

Supporting SPM offers several advantages:

• Faster and more reliable dependency resolution.
• Better integration with modern Xcode workflows.
• Reduced reliance on CocoaPods.
• Improved compatibility with Flutter projects that enable SPM-based plugin integration.
• Better long-term maintainability as Flutter expands SPM support.

Changes

• Added Swift Package Manager configuration for the iOS plugin.
• Updated the package structure and metadata required for SPM compatibility.
• Verified successful integration in Flutter projects using Swift Package Manager.

Testing

Tested with:

• Flutter projects using Swift Package Manager integration.
• iOS builds on recent Xcode versions.
• Existing plugin functionality to ensure no behavioral changes.

Impact

This change is fully backward compatible and does not introduce any API changes. Existing users can continue using the plugin as before, while projects adopting Swift Package Manager can now integrate the plugin successfully.