fix(linkedin-studio): S5 harden carousel — Step-5 caption buzzword gate

S5 close-out (1 edit / 1 file · lint 81/0 · counts 29/19/26/6):
- carousel.md:123 Step 5 De-AI gate: add content rule #4 buzzword line to the caption gate (was missing; grep NONE pre-edit; caption is post-emitting feed text)

Axis-c (buzzword on the caption) closed; axes a/b/d PASS. Class: hybrid guided/stateful + post-emitting on the caption. mcp-image graceful degradation + differentiation-checker wiring verified. 2 deferrals (no-body-link on caption + cosmetic slide line-count). Local-only per push policy.

docs/hardening/log.md

@@ -463,3 +463,82 @@ the value-add is adaptation fidelity (each platform's own rules) + correct routi
   confirmed non-post-emitting (no LinkedIn predicate imposed).
 
 ---
+
+## Session 5 — Create II (`carousel`)
+
+> S5 status: re-grounded the proposed predicates against the actual `carousel.md` lines BEFORE
+> talk (jerndisiplin: assert-after-read). Field-notes inbox **absent** at S5 → graceful no-op (SC-I).
+> All `file:line` below are tool-grounded against the FINAL (post-edit) file.
+> **Class call (operator-agreed):** hybrid **guided/stateful + post-emitting on the caption** — the
+> deck/images are the guided artifact, but the caption IS LinkedIn feed text, so the post predicates
+> apply *to the caption* (not to the slides). Slides are bound by mobile-readability rules, not the
+> feed bar.
+
+### /linkedin:carousel — template→slide-by-slide deck + caption + optional mcp-image, full deck to clipboard
+
+**INTENT.** `carousel` is the Create journey's **document-post path**: from a chosen template
+(How-To / Listicle / Story / Comparison / Framework) + a topic, produce a publish-ready carousel —
+structured slide-by-slide copy (header + body + visual note per slide) + a feed caption + optional
+slide images (mcp-image), all assembled into ONE clipboard payload. Carousels/documents are the
+top organic format (~7%; `references/algorithm-signals-reference.md`). Hybrid class: the deck is the
+guided/stateful artifact; the **caption is post-emitting** and must honor the content bar mechanically
+on the caption (hook **110–140**, no banned buzzword, topic→5 pillars) + graceful mcp-image degradation.
+
+**SIMULATE.**
+- **Persona (ICP):** the author — 1048 followers, "Validation", 5 pillars; direct/technical NO/EN voice.
+  Builds a **How-To Guide** carousel on a pillar topic; tested both mcp-image-available and -unavailable.
+- **Invocation:** `/linkedin:carousel` → pick template 1 (How-To) → topic + audience.
+- **Walk:** Step 0 (`:24`) load state/voice/recent → Step 1 (`:30`) AskUserQuestion template → Step 2
+  (`:50`) topic+audience → Step 3 (`:58`) slide copy → Step 4 (`:94`) caption (hook 110–140 `:97`, band
+  300–500 `:103`) → **Step 5 quality + De-AI gate (the gap)** → Step 5.5 (`:127`) mcp-image (graceful)
+  → Step 6 (`:156`) present full deck → clipboard one-payload (`:191–213`) → Step 7 (`:218`) state.
+- **CONCRETE friction (spec-level, anchored — not a generated deck):** at **Step 5** the De-AI /
+  Differentiation gate (pre-edit `:121–123`) confirmed *personal substance · original thinking ·
+  concrete specifics · genuine voice* and banned mechanical engagement-bait, but had **no buzzword
+  line** — `grep -niE "buzzword|leverage|synergy|paradigm"` over the whole file = **NONE**. So a
+  caption opening *"How to leverage AI to drive synergy across the public-sector ecosystem…"* would
+  pass Step 5 unflagged; content rule #4 (`CLAUDE.md:124`) was never enforced at the caption gate.
+  Same failure class S2/S3 fixed in `post`/`react`. (Caption generation in Step 4 is exactly where a
+  rewrite can slip buzzwords in.)
+- **No dead-ends:** all 5 referenced files exist (`agents/differentiation-checker.md`,
+  `assets/templates/carousel-templates.md`, `references/algorithm-signals-reference.md`,
+  `hooks/scripts/clipboard-helper.mjs`, `hooks/scripts/state-updater.mjs` — `[ -f ]` all FINNES).
+
+**EVALUATE (4 axes).**
+- **(a) intention fidelity — PASS.** Template→slides→caption→full-deck-clipboard-as-one-payload
+  (`:191–213`, explicitly "the whole carousel, not just the caption") + state — delivers the promise.
+- **(b) algorithm bar — PASS.** ~7% (`:37`) matches the ref exactly (`algorithm-signals-reference.md:55`,
+  "Documents / carousels | Top organic format (~7%…)"); "document post" framing correct (`:170`, LinkedIn
+  removed native carousels Dec 2023); caption hook 110–140 (`:97`).
+- **(c) MECHANICAL predicate (post-emitting, on the caption) — GAP → fixed.** hook band ✓ (`:97`) ·
+  caption band 300–500 ✓ (`:103`) · topic→pillars ✓ (`:26/:56`) · subagent resolves ✓ (`:125`) ·
+  **buzzword ✗** (grep NONE; De-AI gate had no rule-#4 line). *no-body-link not imposed: a carousel
+  caption is not a typical link site and the command never asks for links — minor, deferred (matches
+  S2–S4 which left it untouched).*
+- **(d) agent-wiring + graceful degradation — PASS.** `differentiation-checker` resolves, namespaced,
+  conditional (`:125`, `subagent_type: linkedin-studio:differentiation-checker`). **mcp-image graceful
+  degradation solid:** "If mcp-image is unavailable or fails, skip… degrades to text-only" (`:129`),
+  per-call failure logged + continue, all-fail → text-only Step-6 design-guide branch (`:154`, `:176`).
+  `state-updater` exports `updatePostTracking` (`:55`) + `writeState` (`:346`) — Step-7 wiring correct.
+
+**HARDEN (surgical — 1 edit, 1 file, grep-confirmed landed).**
+- `commands/carousel.md:123` — **extended** the Step-5 De-AI gate with content rule #4:
+  `**Strip corporate buzzwords** from the caption (Content Quality Rule #4: leverage, synergy,
+  paradigm shift, thought leader, disruptive, value proposition, ecosystem, holistic approach) —
+  caption generation can slip them in, and they trip the same low-substance signal.`
+- **Deferrals:** *no-body-link on the caption* (low risk, command never emits links; S2–S4 precedent)
+  + two cosmetic notes recorded, not edited (slide line-count 5 vs 7 between `:73–77` and `:87`; both
+  are NICE-only, below the stopping-rule's axis-pass bar).
+- **CONCRETE after:** the "leverage…synergy…ecosystem" caption now trips the Step-5 buzzword line
+  before the deck is presented.
+
+**VERIFY.**
+- `bash scripts/test-runner.sh` → `Passed: 81 · Failed: 0 · Warnings: 0`; counts **29/19/26/6**
+  unchanged (`ls commands/*.md|wc -l` == 29, `ls agents/*.md|wc -l` == 19; `git diff --stat` =
+  `carousel.md` only, 1 line changed). Only `.md` touched → hooks/analytics `node --test` not needed.
+- Before/after delta: axis (c) buzzword sub-check now enforced at the load-bearing Step-5 caption gate.
+  The 1 edit is the cause.
+- Disposition: **HARDENED** (1 edit, axis-c) · 2 recorded deferrals (no-body-link + cosmetic) · axes
+  a/b/d PASS.
+
+---