[Jeehut]

Summary

This raises the package to the newest Swift tools version. CI moves to the Xcode 27 runner, because the macOS 26 image only has Xcode 26.6, which can't read tools version 6.4.

 Package.swift
-// swift-tools-version: 6.2
+// swift-tools-version: 6.4

 .github/workflows/main.yml
-    runs-on: macos-26
+    runs-on: xcode-27
+      - name: Select Xcode 27.2
+        run: sudo xcode-select -s /Applications/Xcode_27.2.app

Evidence

Locally with Xcode 27.2 (Swift 6.4.2):

• swift build: succeeds
• swift test: 37 of 37 tests pass

Merge Danger

Door: two-way

Blast Radius: consumers

Projects on Xcode 26 or older can no longer resolve the package. This is intended for 3.0.0. The xcode-27 runner is still a GitHub preview image.