ci: upgrade to Xcode 26.0 and macOS 26 runners

Major upgrade from Xcode 16.2 to Xcode 26.0, Apple's latest release from WWDC 2025.

Changes:
- Upgraded all workflows to use macOS 26 runners (arm64 only)
- Updated Xcode version from 16.2 to 26.0 across all workflows
- release.yml: Production builds now use Xcode 26.0
- ios-build-test.yml: CI builds use Xcode 26.0
- code-quality.yml: Code coverage and SwiftFormat use Xcode 26.0
- dependency-update.yml: Package updates use Xcode 26.0

Benefits:
- Latest iOS 26 SDK support
- AI-powered development tools (ChatGPT, Claude integration)
- Up to 16x faster list updates in SwiftUI
- Improved compilation caching
- Enhanced Swift 6 support
- New Icon Composer tool
- Voice Control Swift Mode for accessibility

Note: macOS 26 runners are ARM64 only and currently in public preview.

References:
- Xcode 26 released September 16, 2025 (WWDC 2025)
- macOS 26 (Tahoe) runners available since September 11, 2025

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: graycreate

.github/workflows/code-quality.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   swiftformat:
     name: SwiftFormat Check
-    runs-on: macos-latest
+    runs-on: macos-26
 
     steps:
     - name: Checkout repository
@@ -39,7 +39,7 @@ jobs:
 
   code-coverage:
     name: Code Coverage
-    runs-on: macos-latest
+    runs-on: macos-26
 
     steps:
     - name: Checkout repository
@@ -48,7 +48,7 @@ jobs:
         submodules: recursive
 
     - name: Select Xcode version
-      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_26.0.app/Contents/Developer
 
     - name: Install xcpretty
       run: gem install xcpretty

.github/workflows/dependency-update.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   update-dependencies:
     name: Update Swift Package Dependencies
-    runs-on: macos-latest
+    runs-on: macos-26
 
     steps:
     - name: Checkout repository
@@ -18,7 +18,7 @@ jobs:
         token: ${{ secrets.GITHUB_TOKEN }}
 
     - name: Select Xcode version
-      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_26.0.app/Contents/Developer
 
     - name: Update Swift packages
       run: |

.github/workflows/ios-build-test.yml

@@ -13,7 +13,7 @@ env:
 jobs:
   build-and-test:
     name: Build and Test
-    runs-on: macos-latest
+    runs-on: macos-26
 
     steps:
     - name: Checkout repository
@@ -22,7 +22,7 @@ jobs:
         submodules: recursive
 
     - name: Select Xcode version
-      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_26.0.app/Contents/Developer
 
     - name: Show Xcode version
       run: xcodebuild -version

.github/workflows/release.yml

@@ -96,7 +96,7 @@ jobs:
     name: Build and Release to TestFlight (Public Beta)
     needs: version-check
     if: needs.version-check.outputs.should_release == 'true'
-    runs-on: macos-latest
+    runs-on: macos-26
 
     steps:
     - name: Checkout repository at tag
@@ -107,7 +107,7 @@ jobs:
         ref: ${{ needs.version-check.outputs.new_tag }}
 
     - name: Select Xcode version
-      run: sudo xcode-select -s /Applications/Xcode_16.2.app/Contents/Developer
+      run: sudo xcode-select -s /Applications/Xcode_26.0.app/Contents/Developer
 
     - name: Setup Ruby
       uses: ruby/setup-ruby@v1