feat(ios): add SwiftPM package support

[trancee]

Summary

• move SwiftPM manifests to the repository root
• add the XCFramework packaging helper and CI validation
• automate SwiftPM release asset upload on published GitHub releases
• remove CocoaPods references from release/docs guidance

Verification

• yamllint -c .yamllint.yml .github/workflows/*.yml
• git diff --check
• swift package dump-package --package-path .
• pre-push verification and docs checks via hooks