fix: adapt Flutter architecture verification for Xcode 27

Signed-off-by: Tom Brow <tomb@block.xyz>

.github/workflows/_ci-clients.yml

@@ -150,6 +150,8 @@ jobs:
         run: /bin/bash scripts/test-mobile-pagination.sh
       - name: Trust pinned Swift source-copy plugin
         run: python3 scripts/trust-ios-package-plugin.py --trust-file "$HOME/Library/org.swift.swiftpm/security/plugins.json"
+      - name: Use Xcode 27 lipo compatibility adapter for Flutter
+        run: echo "$GITHUB_WORKSPACE/scripts/apple-tools" >> "$GITHUB_PATH"
       - name: Build complete iOS simulator app
         run: cd mobile && flutter build ios --simulator --debug --no-pub --verbose
       - name: Test native pagination accessibility

CONTRIBUTING.md

@@ -622,3 +622,8 @@ The iOS Swift dependency uses `SharedSourcesPlugin` to copy its shared Swift sou
 Xcode users must approve this plugin when prompted. CI trusts only its reviewed
 commit fingerprint using `scripts/trust-ios-package-plugin.py`; package upgrades
 require reviewing the plugin before updating that fingerprint.
+
+Flutter 3.41 requires the repository’s `scripts/apple-tools` directory first on
+`PATH` for manual iOS builds with Xcode 27. Its `lipo` adapter verifies each
+architecture separately because Xcode 27 rejects Flutter’s combined verification
+command. `just mobile-dev` and CI configure this automatically.

Justfile

@@ -1027,6 +1027,7 @@ mobile-build-android:
 mobile-dev:
     #!/usr/bin/env bash
     set -euo pipefail
+    export PATH="{{justfile_directory()}}/scripts/apple-tools:$PATH"
     ./scripts/check-xcode.sh
     if ! pgrep -x Simulator &>/dev/null; then
         open -a Simulator

scripts/apple-tools/lipo

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Flutter 3.41 passes multiple architectures to -verify_arch. Xcode 27's
+# lipo accepts only one at a time. Preserve the all-architectures requirement.
+set -euo pipefail
+if [[ $# -ge 3 && "$2" == -verify_arch ]]; then
+  binary="$1"
+  shift 2
+  for architecture in "$@"; do
+    xcrun lipo "$binary" -verify_arch "$architecture"
+  done
+else
+  exec xcrun lipo "$@"
+fi