pm-social was the last bundle without a .claude-plugin/plugin.json (a latent
gap that can block clean plugin installation). Adds it, matching the
marketplace.json entry (version 1.0.0). Independent of PR #23.
Claude-Session: https://claude.ai/code/session_016JWn5jRD5tcEFKrubjQ6Px
Co-authored-by: Claude <noreply@anthropic.com>
mohitagw15856