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.

Start with run_release.py and inspect command construction for the python.org upload and release-manager SSH paths. Use mocked Paramiko clients to capture exec_command() output with metacharacters in credentials, tokens, usernames, and staging paths; done means those values are safely quoted while intentional glob expansion for staged artifact copies remains intact.