[FEATURE] Add 'Always allow (global)' option to permission prompt for user-level settings

Summary

When Claude Code prompts for permission, the current options are:

• Allow once
• Allow for session
• Always allow (saves to project settings .claude/settings.json)

There is no option to save the permission to user-level settings (~/.claude/settings.json), which means commonly-allowed commands must be manually added to the user settings file outside of Claude Code.

Proposed Change

Add a fourth option to the permission prompt:

• Allow once
• Allow for session
• Always allow (project)
• Always allow (global) → saves to ~/.claude/settings.json

This would let users build up their global permission rules organically as they work, rather than having to manually edit ~/.claude/settings.json.

Motivation

• Users who work across many projects end up re-approving the same commands (e.g., npm run build, git commit, tsc) in every new project
• The current "Always allow" only persists at the project level, so switching projects means starting over
• Manually editing ~/.claude/settings.json is workable but breaks the flow — you have to leave Claude Code, open the file, figure out the right glob pattern, and come back
• This was previously requested in #2218 which was auto-closed due to inactivity, but the underlying need was never addressed

Example UX

Claude wants to run: npm run build

  1. Allow once
  2. Allow for session
  3. Always allow (this project)
  4. Always allow (all projects)

Option 4 would append "Bash(npm run build)" to the permissions.allow array in ~/.claude/settings.json.