Add option to disable terminal title changes

Summary

When Claude Code starts, it briefly shows the original terminal title, then switches it to "claude code". There's currently no way to prevent this behavior.

Request

Add a configuration option to disable or customize the terminal title behavior. This could be:

• A setting in the config file (e.g., terminalTitle: false or terminalTitle: "custom title")
• A CLI flag (e.g., --no-title or --title "custom")
• An environment variable

Use Case

Users may want to:

• Keep their existing terminal title (showing current directory, git branch, etc.)
• Use a custom title scheme managed by their shell
• Prevent any application from modifying their terminal title

Current Behavior

1. Terminal has a title set by the user's shell/config
2. Claude Code starts
3. Title briefly flashes, then changes to "claude code"
4. Original title is not restored on exit

Expected Behavior

With a configuration option enabled, Claude Code would not modify the terminal title at all.