Bug: release tooling should quote remote command arguments

run_release.py builds remote shell command strings for release publication.
Several values are interpolated directly into those command strings, including
release credential environment values, the release tag, and remote staging paths
derived from release-manager state.

Those values are normally trusted release-process inputs, but quoting them
consistently makes the generated commands safer and more predictable when a
value contains whitespace or shell metacharacters.

Reproducer

Using mocked Paramiko clients:

1. Set the python.org API credential value to contain shell metacharacters, such
   as user:key; echo unexpected.
2. Make the fake Sigstore issuer return a token containing shell metacharacters,
   such as token; touch /tmp/unexpected.
3. Run the python.org upload step and capture the command sent to
   exec_command().
4. The captured command includes those values unquoted in AUTH_INFO=... and
   SIGSTORE_IDENTITY_TOKEN=... assignments.

Similar mocked tests can set the release-manager SSH username to a value with a
metacharacter and observe that derived staging paths are inserted into cleanup,
copy, unzip, move, group, and permission commands without quoting.

Expected behavior

Release-tool commands should quote environment values, release arguments, and
remote filesystem paths before sending command strings to the remote shell,
while preserving intentional glob expansion for staged artifact copies.

run_release.py から始め、python.org へのアップロードと release-manager の SSH パスに対するコマンド構築を調査します。モックした Paramiko クライアントを使用して、認証情報、トークン、ユーザー名、ステージングパスにメタ文字を含めた場合の exec_command() の出力を取得します。完了条件は、意図したステージ済みアーティファクトのコピーに対する glob 展開を維持したまま、それらの値が安全にクォートされていることです。