## Why
Remote credential masking previously supported only Bash commands without login startup or shell snapshots, leaving Zsh commands with unmasked credentials.
## What changed
- Enable masking for Zsh login commands using shell snapshots on Linux and macOS.
- Capture trusted startup profiles per launch, bind the credential broker to the resulting environment, and replace credentials and supported aliases with placeholders before snapshot replay.
- Preserve explicit environment overrides, credential unsets, and launcher-managed proxy settings during replay.
- Warn and fall back to unmasked startup when a snapshot cannot safely replay credentials; stop execution if protected snapshot restoration fails.
## Testing
Extend remote execution tests for inherited and profile-defined credentials, overrides, destination changes, and unsupported-profile fallback. Add a Zsh scenario snapshot showing a credential placeholder in command output.
GitOrigin-RevId: 83193d6cbc05f3deb0d6d0b9ae80974b353ce900
viyatb-oai
1c5ca2a979