install_build_tools_linux ran run_quiet_step and then returned 0
unconditionally from every package-manager branch, so a failed build-tool
install was printed as an error and immediately overwritten with a success
line. The installer emitted "Installing build tools failed" followed by
"Build tools installed", and the caller's "Continuing without auto-installing
build tools" warning was unreachable. The npm-failure recovery path likewise
reported "Build tools setup complete" and retried an install that could not
succeed. install_build_tools_macos already propagated its status; only the
Linux sibling swallowed it.
Return the package manager's exit status and collapse the five duplicated
is_root/sudo branches into one command list, which removes the bug class
rather than patching a single branch.
Verified against the live openclaw.ai script: a stubbed apt-get failure
reproduced the false success before the change and reports the honest warning
after it.
Peter Steinberger
af3118b187