refactor(linkedin): single newsletter entry + skill trigger + router row (S11)

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

@@ -79,6 +79,7 @@ Present these options to the user:
 | `/linkedin:pipeline` | Full end-to-end workflow from idea to post-publish analysis |
 | `/linkedin:carousel` | Create structured multi-slide carousel with visual layout guidance |
 | `/linkedin:video` | Create video scripts with hook, body, CTA, captions, and thumbnail suggestions |
+| `/linkedin:newsletter` | Long-form orchestrator — newsletter editions, essays, series articles (research → draft → fact-check → persona-review → lock → delivery). The single long-form entry point |
 | `/linkedin:batch` | Create a full week of content in one session |
 | `/linkedin:calendar` | View and manage your post scheduling queue |
 | `/linkedin:publish` | Mark scheduled posts as published |
@@ -110,7 +111,7 @@ Present these options to the user:
 | `/linkedin:monetize` | Monetization strategy for 10K+ followers |
 | `/linkedin:speaking` | Generate speaking opportunities via LinkedIn |
 | `/linkedin:collab` | Orchestrate collaborations with other thought leaders |
-| `/linkedin:multiplatform` | Adapt content for Twitter/X, newsletter, blog, YouTube |
+| `/linkedin:multiplatform` | Adapt content for Twitter/X, slides, YouTube (short-form/cross-format; long-form → `/linkedin:newsletter`) |
 
 ## Ask the User
 
@@ -142,6 +143,7 @@ Use AskUserQuestion to ask:
 21. **A/B test** — Design, track, or analyze content experiments
 22. **Create a video** — Script for talking head, screen recording, or slideshow
 23. **Mark published** — I just published a scheduled post
+24. **Write long-form** — Newsletter edition, essay, or series article (`/linkedin:newsletter`)
 
 Based on their answer, guide them to the appropriate command or invoke it directly.