feat(linkedin-studio): S14 — journey layer (create/measure front-doors + 5-journey router), v4.1.0

14a's cold command-rationalization found ZERO redundancy across the 27 commands
(no defensible merge/cut), so the operator reframed S14 from "merge/cut" to
"add a journey layer over the kept atomics".

- Add /linkedin:create + /linkedin:measure — delegate-only guided front-doors
  (Read/Glob/AskUserQuestion only; route to the command that owns the work)
- Re-tier commands/linkedin.md into 5 journeys (Start/Create/Engage/Measure/Grow);
  onboarding/strategy elevated as Start/Grow front-doors; Engage = calendar+firsthour tier
- 14a honesty nits: router now lists firsthour; calendar cross-links to firsthour;
  competitive confirmed UNGATED (the claimed 1K-gating inconsistency was unfounded)
- Lockstep: EXPECT_COMMANDS 27->29, v4.0.0->4.1.0 across plugin.json / README badges /
  plugin+root CLAUDE.md / README / CHANGELOG; new README commands-badge lint guard
- 14a deliverable corrected: multiplatform entry added (26/27 -> 27/27), header counts,
  competitive nit withdrawn
- Independent /trekreview (2 Opus reviewers) raised 3 MAJORs (stale commands badge,
  router competitive self-contradiction, STATE.md count) — ALL remediated in-session;
  verdict ALLOW

Gate: test-runner.sh 74/0/0; node --test 98/98; commands=29; v4.1.0 consistent.
Additive/minor — no command removed/renamed/behavior-changed; reload registers create+measure.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plugins/linkedin-studio/commands/measure.md

@@ -0,0 +1,51 @@
+---
+name: linkedin:measure
+description: |
+  Performance front-door — one guided entry for when you want to understand how you're
+  doing on LinkedIn. Asks what you need and routes you to the command that owns that
+  analysis (import, report, analyze/troubleshoot, audit, or A/B test). It does NOT
+  crunch numbers itself — it hands off to the command that owns the work.
+  Triggers on: "measure", "how am I doing", "my performance", "show my analytics",
+  "performance overview", "how are my posts doing", "linkedin measure".
+allowed-tools:
+  - Read
+  - Glob
+  - AskUserQuestion
+---
+
+# Measure — Performance Front-Door
+
+You are the entry point for the **Measure** journey (the measure → improve loop). The
+user wants insight into performance but may not know which command fits. Identify the
+intent in one question and route. **You do not run the analysis here.**
+
+## Step 0: Quick context (optional)
+
+If `assets/analytics/` holds imported data, you may note "last import: [date]" in one
+line so the user knows whether a fresh import is needed first. Do not block on it.
+
+## Step 1: Identify what they need
+
+Use `AskUserQuestion` — **"What do you want to do?"**
+
+1. **Import new data** — load a LinkedIn analytics CSV export → `/linkedin:import`
+2. **See a report** — weekly/monthly numbers, trends, top performers → `/linkedin:report`
+3. **Diagnose a problem** — reach dropped / low engagement, what's wrong → `/linkedin:analyze`
+4. **Strategy audit** — periodic top/bottom posts, topic & format mix review → `/linkedin:audit`
+5. **A/B test** — design, log, or review a content experiment → `/linkedin:ab-test`
+
+## Step 2: Route
+
+State the chosen command and one line of why, then **proceed into that command's
+workflow**. Do NOT duplicate the analysis logic — each command owns it.
+
+| Intent | Command |
+|--------|---------|
+| Import a CSV export | `/linkedin:import` |
+| Weekly / monthly report | `/linkedin:report` |
+| Troubleshoot performance | `/linkedin:analyze` |
+| Quarterly strategy audit | `/linkedin:audit` |
+| Content experiment | `/linkedin:ab-test` |
+
+**Order note:** reporting needs imported data. If the user wants a report but nothing
+has been imported yet, route to `/linkedin:import` first, then `/linkedin:report`.