Add git install support to install-cli and align git messaging

[travisp]

Summary

• add git install support to install-cli.sh (flags/envs match install.sh)
• add a docker smoke test for the CLI git install path
• clarify git install logs to indicate local checkout when --git-dir points to a repo

Testing

• docker build -t clawdbot-install-cli-git-smoke -f scripts/docker/install-cli-git-smoke/ Dockerfile .
• docker run --rm -t -e CLAWDBOT_GIT_REF=v2026.1.24 clawdbot-install-cli-git-smoke
• scripts/e2e/install-cli-docker.sh

Note: this was supported with gpt-5.2-codex, but I understand the code, ran the docker smoke test, and then tested an install on a vm

[vercel]

@travisp is attempting to deploy a commit to the Amantus Machina Team on Vercel.

A member of the Team first needs to authorize it.

[thewilloftheshadow]

Landed via temp rebase onto main.

• Related tests: not run (no test suite in this repo)
• Land commit: 446dfd2
• Merge commit: 5838d22

Thanks @travisp!