Feature request: Project-specific startup menu/message for onboarding new users

Summary

When starting Claude Code in a repository, there's no visible way to display project-specific guidance or onboarding information to users. This would help teams onboard new developers and remind users of available project-specific skills, workflows, or conventions.

Use Case

I maintain multiple repositories (100+), each with different Claude skills, workflows, and conventions defined in their .claude/ directories. When someone starts Claude Code in a specific repo, I'd like them to see a brief menu or message explaining:

• Available project-specific skills (e.g., "Use case-study-generator to add case studies")
• Common workflows or commands
• Project conventions

Current Behavior

• SessionStart hooks run and output goes into Claude's context, but nothing is visible to the user in the terminal
• companyAnnouncements also doesn't display visibly
• The only workaround is shell aliases/functions, which don't scale across many repos

Proposed Solution

A project-level config option (in .claude/settings.json or .claude/settings.local.json) that displays a visible startup message or menu when Claude Code starts in that directory. Something like:

{
  "startupMessage": "📚 Welcome to intelligent-textbooks!\n\nAvailable skills:\n- case-study-generator: Add case studies from GitHub repos\n- quiz-generator: Generate chapter quizzes\n\nRun /skills for more info."
}

Or a more structured menu format that lists available skills/commands.

Benefits

• Better onboarding for teams using Claude Code
• Discoverability of project-specific skills and workflows
• Scales across many repositories without global shell configuration
• Keeps guidance close to the code (in the repo's .claude/ directory)

Environment

• Claude Code v2.1.21
• macOS