chore: normalize project.pbxproj ordering

.github/workflows/pbxproj-canonical.yml

@@ -0,0 +1,39 @@
+name: pbxproj canonical
+
+on:
+  pull_request:
+    paths:
+      - "iOS_SDK/OneSignalSDK/OneSignal.xcodeproj/**"
+      - "Gemfile"
+      - "Gemfile.lock"
+      - ".github/workflows/pbxproj-canonical.yml"
+  push:
+    branches:
+      - main
+    paths:
+      - "iOS_SDK/OneSignalSDK/OneSignal.xcodeproj/**"
+      - "Gemfile"
+      - "Gemfile.lock"
+      - ".github/workflows/pbxproj-canonical.yml"
+
+jobs:
+  check:
+    name: OneSignal.xcodeproj is gem-canonical
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.3"
+          bundler-cache: true
+
+      - name: Ensure OneSignal.xcodeproj save is a no-op
+        run: |
+          bundle exec ruby -e 'require "xcodeproj"; Xcodeproj::Project.open("iOS_SDK/OneSignalSDK/OneSignal.xcodeproj").save'
+          if ! git diff --exit-code -- iOS_SDK/OneSignalSDK/OneSignal.xcodeproj; then
+            echo "::error::OneSignal.xcodeproj is not canonical for the pinned xcodeproj gem. Open and save with: bundle exec ruby -e 'require \"xcodeproj\"; Xcodeproj::Project.open(\"iOS_SDK/OneSignalSDK/OneSignal.xcodeproj\").save'"
+            exit 1
+          fi

Gemfile

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+# Pin so OneSignal.xcodeproj "canonical" order is reproducible across machines.
+# Older xcodeproj (e.g. 1.25) rewrites HEADER_SEARCH_PATHS quoting on save.
+# Do not gem-normalize examples/demo/App.xcodeproj — that project is XcodeGen-owned.
+gem "xcodeproj", "1.28.1"

Gemfile.lock

@@ -0,0 +1,30 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    CFPropertyList (3.0.8)
+    atomos (0.1.3)
+    base64 (0.3.0)
+    claide (1.1.0)
+    colored2 (3.1.2)
+    nanaimo (0.4.0)
+    nkf (0.3.0)
+    rexml (3.4.4)
+    xcodeproj (1.28.1)
+      CFPropertyList (>= 2.3.3, < 4.0)
+      atomos (~> 0.1.3)
+      base64
+      claide (>= 1.0.2, < 2.0)
+      colored2 (~> 3.1)
+      nanaimo (~> 0.4.0)
+      nkf
+      rexml (>= 3.3.6, < 4.0)
+
+PLATFORMS
+  ruby
+  x86_64-darwin-23
+
+DEPENDENCIES
+  xcodeproj (= 1.28.1)
+
+BUNDLED WITH
+   2.7.2