[BUG] Marketplace update fires unconditional `ssh -T git@github.com` probe despite CLAUDE_CODE_PLUGIN_PREFER_HTTPS=1

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The plugin marketplace update path executes an unconditional ssh -T git@github.com connectivity probe before fetching a marketplace, even when
CLAUDE_CODE_PLUGIN_PREFER_HTTPS=1 is set and the marketplace's origin is already an HTTPS URL. The probe doesn't affect functional outcome
(the HTTPS fetch succeeds either way), but it noisily wakes the user's SSH agent — for users on 1Password / gnome-keyring this means a popup or
authorization prompt every time the marketplace is refreshed.

What Should Happen?

When CLAUDE_CODE_PLUGIN_PREFER_HTTPS=1 is set (or the resolved marketplace remote is already HTTPS), skip the ssh -T git@github.com probe
entirely.

Error Messages/Logs

strace -fe trace=execve,connect on the claude process tree captures the probe:

[pid 107447] execve("/run/current-system/sw/bin/ssh", ["ssh", "-T", "-o", "BatchMode=yes", "-o", "ConnectTimeout=2", "-o", "StrictHostKeyChecking=yes", "git@github.com"], ...) = 0
[pid 107447] connect(4, {sa_family=AF_UNIX, sun_path="/home/$USER/.1password/agent.sock"}, 110) = 0

Meanwhile, the actual fetch is pure HTTPS:
trace: run_command: GIT_DIR=.git git remote-https origin https://github.com//.git

So the SSH probe is purely informational — it never affects the fetch path.

Steps to Reproduce

1. Configure a custom marketplace with a github source (HTTPS remote in the resulting marketplace clone).
2. Set CLAUDE_CODE_PLUGIN_PREFER_HTTPS=1.
3. Click "Update marketplace" (or trigger marketplace auto-update).
4. Observe an SSH agent authorization prompt every time, even though no SSH access is used for the actual fetch.

Claude Model

Not sure / Multiple models

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.137

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

_No response_