[CLI] Feature Request: Add --branch / --ref flag for jules new

[hsm207]

🚀 Feature Request: Add --branch / --ref flag for jules new

📉 The Problem

It is currently impossible to specify a target branch when initiating a new session via the CLI. The CLI always defaults to main, forcing users to include git checkout <branch> in the task prompt.

⏳ Troubleshooting Overhead

We spent considerable development time troubleshooting persistent patch collision issues, eventually tracing the root cause back to the CLI's inability to target a specific branch natively.

• Technical Root Cause: The remote agent operates on an outdated base (main) rather than the intended feature branch.
• Engineering Impact: Task instructions are misapplied or ignored despite being present in the prompt, leading to complex recovery efforts and fragmented git history.

🎯 Expected Behavior

Since the Web UI allows branch selection, the CLI should support a --branch or --ref flag to set the base context for the remote agent natively.

🏛️ Impact

Professional workflows involving feature branches are significantly hampered by this omission. Providing a native CLI mechanism for branch selection would:

1. Improve reliability of automated patch application.
2. Reduce troubleshooting overhead for engineering teams.
3. Ensure synchronization between local development states and remote agent environments.