Linux install fails when $HOME is a root-owned symlink under /home (activation transaction I/O failed) #2306

Summary

install fails on Linux when $HOME is a root-owned symlink under /home (for example /home/alice -> /local/home/alice, common on corporate/managed dev hosts):

error: failed to stage install candidate: activation transaction I/O failed

Cause

activation_posix_walk_path() only resolves trusted aliases when /tmp, /var or /home is itself a symlink (the #2175 fix). When /home is a real directory and the per-user entry /home/<user> is the root-owned symlink, the O_NOFOLLOW walk in activation_directory_secure() rejects it and reports the generic I/O error.

Repro

• /home is a real root-owned dir, /home/alice is a root-owned symlink to /local/home/alice
• HOME=/home/alice, v0.11.0
• curl -fsSL .../install.sh | bash

Workaround

bash -s -- --dir "$(realpath ~/.local/bin)"

Suggested fix

On Linux, also resolve a root-owned symlink at /home/<name> when its target is a root- or user-owned directory. Arbitrary user-owned symlinks stay rejected.