/plugin marketplace clone fails: uses SSH instead of HTTPS for public repo

Bug

The /plugin command fails to load the official marketplace because it clones via SSH (git@github.com:...) instead of HTTPS. This means users without SSH keys configured for GitHub cannot browse or install plugins from the public marketplace.

Steps to reproduce

1. Fresh macOS install, no SSH keys in ~/.ssh/
2. gh auth login works fine (HTTPS)
3. Run /plugin in Claude Code

Expected

Marketplace loads — it's a public repo, HTTPS clone should work without any auth.

Actual

Failed to load marketplace "claude-plugins-official" from source (github):
Failed to clone marketplace repository: SSH authentication failed.

Original error: Cloning into '...anthropics-claude-plugins-official'...
ssh: connect to host github.com port 22: Undefined error: 0
fatal: Could not read from remote repository.

Workaround attempted

Setting git config --global url."https://github.com/".insteadOf "git@github.com:" does not help — the plugin system appears to call SSH directly rather than going through git clone, so git's URL rewrite rules are bypassed.

Environment

• Claude Code (latest, Feb 2026)
• macOS 15 (Darwin 25.3.0), Apple Silicon
• gh CLI authenticated via HTTPS with valid token
• No SSH keys configured (shouldn't be required for a public repo)

Suggestion

The marketplace loader should clone public repos over HTTPS (https://github.com/anthropics/claude-plugins-official.git) rather than SSH. SSH should only be used as a fallback or for private repos.