Support for cryptographically signing commits (GPG, SSH, S/MIME)

[VihaanReddyM]

Since Zed already includes a Git panel, offering a complete Git experience feels essential — and commit signing is a major part of that for many users. Not having support for GPG, SSH, or S/MIME signing can be a deal-breaker, or at the very least, a significant inconvenience for people like me who rely on signed commits across all workflows.

This isn’t a new request either: issues #37899 and #26114 show that there is consistent interest from the community. Even if not everyone uses commit signing, those who do often consider it mandatory.

Adding support would bring Zed closer to feature parity with other editors, streamline workflows for security-focused users, and make Zed more appealing as a primary development environment.