build: allow provisioning updates and use app-store-connect export method

-allowProvisioningUpdates lets xcodebuild create the Mac App Store
provisioning profile for com.dkelkhoff.markdownViewr on first export.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ExportOptions-MAS.plist

@@ -3,7 +3,7 @@
 <plist version="1.0">
 <dict>
     <key>method</key>
-    <string>app-store</string>
+    <string>app-store-connect</string>
     <key>teamID</key>
     <string>9MG4YT2G93</string>
     <key>signingStyle</key>

justfile

@@ -160,12 +160,14 @@ release-mas: kill
         -configuration Release-MAS \
         -archivePath "$ARCHIVE" \
         -destination 'generic/platform=macOS' \
+        -allowProvisioningUpdates \
         CURRENT_PROJECT_VERSION="$BUILD_NUMBER" | xcpretty || true
     echo "==> Exporting App Store package..."
     xcodebuild -exportArchive \
         -archivePath "$ARCHIVE" \
         -exportPath "$EXPORT" \
-        -exportOptionsPlist ExportOptions-MAS.plist
+        -exportOptionsPlist ExportOptions-MAS.plist \
+        -allowProvisioningUpdates
     PKG=$(find "$EXPORT" -name '*.pkg' | head -1)
     echo ""
     echo "Done! Signed App Store package:"