feat(linkedin): progressive onboarding — hide score until 3+ posts, suppress voice guardian noise

- session-start.mjs: count published posts, gate personalization score
  display and reminder behind >= 3 published posts
- voice-guardian.md: suppress LOW CONFIDENCE messages, silently skip
  drift scoring when < 5 samples
- state-file.template.md: add "general" default for expertise_areas
- onboarding.md: show friendly defaults message for new users, move
  score dashboard to returning-user flow

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

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

@@ -22,6 +22,21 @@ Read `~/.claude/linkedin-thought-leadership.local.md` for current state.
 
 **Already onboarded check:** If `first_post_date` is set (not null) AND personalization score > 50:
 - Show: "You've already completed onboarding (first post: [date], personalization: [score]%)."
+- If `## Recent Posts` has 3+ entries, show the personalization score dashboard:
+  ```
+  Personalization Score: [XX]%
+
+  Category          Weight  Status
+  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+  Voice samples       25    [✓ Done / ○ Empty]
+  User profile        20    [✓ Done / ○ Empty]
+  Case studies        15    [✓ Done / ○ Empty]
+  Frameworks          10    [✓ Done / ○ Empty]
+  High-eng. posts     10    [✓ Done / ○ Empty]
+  Demographics         8    [✓ Done / ○ Empty]
+  Engagement patterns  7    [✓ Done / ○ Empty]
+  Post templates       5    [✓ Done / ○ Empty]
+  ```
 - Use AskUserQuestion: "Would you like to re-run a specific phase?"
   1. Re-optimize profile (360Brew) → jump to Phase 1
   2. Improve personalization → jump to Phase 2
@@ -68,6 +83,20 @@ After each item, ask if done or needs to skip. Don't block — mark skipped item
 ╚═════════════════════════════════════════════╝
 ```
 
+Count published posts by checking `## Recent Posts` entries in state file.
+
+**If fewer than 3 published posts (new user):**
+
+Show: "Your plugin is ready to use with sensible defaults. Personalization makes content more authentic — we'll suggest improvements after you've published a few posts."
+
+Use AskUserQuestion:
+1. **Set up voice profile** (optional, recommended later) — 5 questions about your writing style
+2. **Set up user profile** (optional, recommended later) — Your name, industry, expertise areas
+3. **Both** — Do voice + user profile now
+4. **Skip for now** — Use defaults, I'll run `/linkedin:setup` when ready
+
+**If 3+ published posts (returning user):**
+
 Calculate personalization score:
 ```bash
 node --input-type=module -e "