feat(linkedin-thought-leadership): onboarding improvements for new users

- Session-start hook: welcome message with getting-started steps on first run
- Session-start hook: prominent personalization score section when score is 0
- Router: condensed 4-option menu for users who haven't posted yet
- Post/quick commands: non-blocking readiness check for unpersonalized state
- Post-creation hook: inline 5x5x5 engagement ritual explanation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/linkedin-thought-leadership/commands/post.md

@@ -23,6 +23,16 @@ You are a LinkedIn thought leadership content creator. Guide the user through cr
 First, load persistent state and personalization:
 - Read `~/.claude/linkedin-thought-leadership.local.md` for posting state (streak, weekly progress, recent topics)
 - Read `skills/linkedin-thought-leadership/SKILL.md` for user profile, voice settings, and preferences
+- Read `config/user-profile.local.md` (if it exists) for expertise areas and audience
+
+### Readiness Check
+
+If `config/user-profile.local.md` doesn't exist OR `assets/voice-samples/authentic-voice-samples.md` contains `[Your Name]` in the title line, show this non-blocking notice:
+
+> This plugin isn't personalized yet. Content will use generic best practices.
+> Run `/linkedin:setup` after this session to unlock voice-matched content.
+
+Then proceed normally — do not block content creation.
 
 Check state for topic planning:
 - Compare intended topic against "Recent Posts" in state file