Bundler: install QtWebEngineProcess as executable

file(INSTALL) without a type installs 0644; Chromium then can't launch
its helper process ("LaunchProcess: failed to execvp").

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cmake/bundle-install.cmake.in

@@ -87,7 +87,9 @@ file(GET_RUNTIME_DEPENDENCIES
 set(helper_executables "")
 if(resolved MATCHES "libQt6WebEngineCore")
     message(STATUS "Bundling Qt WebEngine (${webengine_process})")
-    file(INSTALL "${webengine_process}" DESTINATION "${prefix}/libexec" FOLLOW_SYMLINK_CHAIN)
+    # TYPE PROGRAM: a plain file(INSTALL) would drop the executable bit.
+    file(INSTALL "${webengine_process}" DESTINATION "${prefix}/libexec" TYPE PROGRAM
+         FOLLOW_SYMLINK_CHAIN)
     list(APPEND helper_executables "${prefix}/libexec/QtWebEngineProcess")
     file(GET_RUNTIME_DEPENDENCIES
         EXECUTABLES ${helper_executables}