fix(ios): embed Firebase SPM package frameworks

Add an RNFB SPM post-install patch that injects an app-target build
phase for Firebase SPM dynamic frameworks. The phase copies frameworks
built under Xcode's PackageFrameworks directory into the app Frameworks
folder when they were not already embedded by CocoaPods.

This fixes release launches where RNFBStorage links FirebaseStorage,
FirebaseStorage links FirebaseAppCheckInterop, but the app bundle does
not contain FirebaseAppCheckInterop.framework. The fix keeps Storage
declaring only the public FirebaseStorage product and avoids requiring
consumers to install App Check or add a Podfile workaround.

Also regenerates the iOS test project so the new embed phase is present.

Author: russellwheatley

packages/app/firebase_spm.rb

@@ -18,6 +18,8 @@
 
 require 'json'
 
+RNFIREBASE_SPM_EMBED_PHASE_NAME = '[RNFB] Embed Firebase SPM Frameworks'
+
 # Read Firebase SPM URL from app package.json (single source of truth).
 # __dir__ resolves to the directory of this file (packages/app/).
 # In monorepos with hoisted dependencies or pnpm, the path from other packages
@@ -46,6 +48,88 @@
 # https://github.com/firebase/firebase-ios-sdk/blob/main/Package.swift
 # (all products use .library(type: .dynamic))
 #
+# Returns true only when `$RNFirebaseDisableSPM` has been explicitly set to `true`.
+#
+# We deliberately check the value (not just `defined?`), so that config generators,
+# Expo plugins, or env-templated Podfiles that emit `$RNFirebaseDisableSPM = false`
+# don't silently switch to CocoaPods.
+def rnfirebase_spm_disabled?
+  defined?($RNFirebaseDisableSPM) && $RNFirebaseDisableSPM == true
+end
+
+def rnfirebase_spm_embed_script
+  <<~'SCRIPT'
+    set -euo pipefail
+
+    package_frameworks_dir="${BUILT_PRODUCTS_DIR}/PackageFrameworks"
+    app_frameworks_dir="${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}"
+
+    if [ ! -d "${package_frameworks_dir}" ]; then
+      exit 0
+    fi
+
+    mkdir -p "${app_frameworks_dir}"
+
+    find "${package_frameworks_dir}" -maxdepth 1 -type d -name "*.framework" -print0 | while IFS= read -r -d '' framework; do
+      framework_name="$(basename "${framework}")"
+      destination="${app_frameworks_dir}/${framework_name}"
+
+      if [ -e "${destination}" ]; then
+        continue
+      fi
+
+      echo "Embedding Firebase SPM framework ${framework_name}"
+      rsync -av --delete \
+        --filter "- Headers" \
+        --filter "- PrivateHeaders" \
+        --filter "- Modules" \
+        "${framework}" \
+        "${app_frameworks_dir}"
+
+      if [ -n "${EXPANDED_CODE_SIGN_IDENTITY:-}" ] && [ "${CODE_SIGNING_REQUIRED:-}" != "NO" ] && [ "${CODE_SIGNING_ALLOWED:-}" != "NO" ]; then
+        /usr/bin/codesign --force --sign "${EXPANDED_CODE_SIGN_IDENTITY}" ${OTHER_CODE_SIGN_FLAGS:-} --preserve-metadata=identifier,entitlements "${destination}"
+      fi
+    done
+  SCRIPT
+end
+
+def rnfirebase_add_spm_embed_phase(installer)
+  return unless defined?(SPM)
+
+  dependencies_by_pod = SPM.instance_variable_get(:@dependencies_by_pod) || {}
+  firebase_spm_enabled = dependencies_by_pod.values.flatten.any? do |dependency|
+    dependency[:url] == $firebase_spm_url
+  end
+  return unless firebase_spm_enabled
+
+  installer.aggregate_targets.each do |aggregate_target|
+    aggregate_target.user_project.native_targets.each do |target|
+      next unless target.respond_to?(:shell_script_build_phases)
+      next unless target.shell_script_build_phases.any? { |phase| phase.name == '[CP] Embed Pods Frameworks' }
+
+      phase = target.shell_script_build_phases.find { |candidate| candidate.name == RNFIREBASE_SPM_EMBED_PHASE_NAME }
+      phase ||= target.new_shell_script_build_phase(RNFIREBASE_SPM_EMBED_PHASE_NAME)
+
+      phase.shell_script = rnfirebase_spm_embed_script
+      phase.shell_path = '/bin/bash'
+      phase.always_out_of_date = '1'
+      phase.input_paths = ['${BUILT_PRODUCTS_DIR}/PackageFrameworks']
+      phase.output_paths = ['${TARGET_BUILD_DIR}/${FRAMEWORKS_FOLDER_PATH}']
+    end
+
+    aggregate_target.user_project.save
+  end
+end
+
+if defined?(SPM) && SPM.respond_to?(:apply_on_post_install) && !SPM.singleton_class.method_defined?(:rnfirebase_original_apply_on_post_install)
+  SPM.singleton_class.alias_method :rnfirebase_original_apply_on_post_install, :apply_on_post_install
+
+  def SPM.apply_on_post_install(installer)
+    rnfirebase_original_apply_on_post_install(installer)
+    rnfirebase_add_spm_embed_phase(installer)
+  end
+end
+
 # @param spec [Pod::Specification] The podspec object (the `s` in podspec DSL)
 # @param version [String] Firebase SDK version (e.g., '12.10.0')
 # @param spm_products [Array<String>] SPM product names (e.g., ['FirebaseAuth'])