Clone repositories from the configured Forgejo instance using the stored
session. The token is passed to git through GIT_CONFIG_* environment-based
config (http.<url>.extraHeader) with GIT_TERMINAL_PROMPT=0, so it never
appears in the remote URL, on the command line, in logs, or in the cloned
repository's .git/config. Git streams its own output and its exit status is
forwarded to the caller.
Supports an optional destination directory plus --branch, --depth and
--origin. Adds tests covering destination handling, exit-status
propagation, remote naming, depth validation and credential redaction.
