Set PRODUCT_NAME to Contextful (fixes ITMS-90129 on macOS)

The Mac App Store requires a globally unique CFBundleName, which follows
PRODUCT_NAME — 'Notes' is taken (by Notes). The module name stays 'Notes'
via PRODUCT_MODULE_NAME so code and tests are untouched; TEST_HOST is
pinned explicitly since xcodegen derives it from the target name.

project.yml

@@ -56,6 +56,10 @@ targets:
         GENERATE_INFOPLIST_FILE: true
         SWIFT_STRICT_CONCURRENCY: complete
         IPHONEOS_DEPLOYMENT_TARGET: "26.0"
+        # The app's PRODUCT_NAME is Contextful; xcodegen derives TEST_HOST
+        # from the target name, so it must be pinned explicitly.
+        TEST_HOST: $(BUILT_PRODUCTS_DIR)/Contextful.app/Contextful
+        BUNDLE_LOADER: $(TEST_HOST)
 
   Notes:
     type: application
@@ -81,6 +85,8 @@ targets:
     settings:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: dev.rzen.indie.Notes
+        PRODUCT_NAME: Contextful
+        PRODUCT_MODULE_NAME: Notes
         INFOPLIST_FILE: Notes/Resources/Info-iOS.plist
         CODE_SIGN_ENTITLEMENTS: Notes/Resources/Notes-iOS.entitlements
         GENERATE_INFOPLIST_FILE: false
@@ -122,7 +128,8 @@ targets:
     settings:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: dev.rzen.indie.Notes
-        PRODUCT_NAME: Notes
+        PRODUCT_NAME: Contextful
+        PRODUCT_MODULE_NAME: Notes
         INFOPLIST_FILE: Notes/Resources/Info-macOS.plist
         CODE_SIGN_ENTITLEMENTS: Notes/Resources/Notes-macOS.entitlements
         GENERATE_INFOPLIST_FILE: false