fix(linkedin-studio): S3 harden react — Step-6 buzzword gate + WebFetch-failure fallback (both paths)

S3 close-out (3 edits / 1 file · lint 81/0 · counts 29/19/26/6):
- react.md:131 Step 6: add no-buzzword checklist line (was missing; banned list = content rule #4; covers Step 6b via "Same as Step 6")
- react.md:60 Step 2: WebFetch-failure fallback (paywall/JS/YouTube-no-transcript -> ask user to paste or pick another; never fabricate)
- react.md:194 Step 2b: same fallback pointer for the multi-URL comparison path

Axis-c (buzzword) + axis-d (graceful degradation) closed on both paths; axes a/b PASS. Shared scorecard already clean post-S2. Local-only per push policy.

docs/hardening/log.md

@@ -312,3 +312,77 @@ CTA without bait, de-AI substance signals).
 - Disposition: **HARDENED** (4 edits, axis-c + shared-asset consistency) · 0 deferrals · axes a/b/d PASS.
 
 ---
+
+## Session 3 — Create I (`react`)
+
+> S3 status: re-grounded STATE's S3 predicate against the actual `react.md` lines BEFORE talk
+> (jerndisiplin: assert-after-read). Field-notes inbox **absent** at S3 → graceful no-op (SC-I).
+> All `file:line` below are tool-grounded against the FINAL (post-edit) file.
+
+### /linkedin:react — URL-to-post pipeline (single + comparison), your-take-as-hook, 1,200–1,800 chars
+
+**INTENT.** `react` is the Create journey's **URL→post path**: fetch external content
+(article / news / research / YouTube), extract the key points, pick an angle, and draft in the
+author's voice. Post-emitting (medium **1,200–1,800**), two paths — single-URL (Steps 1–8) +
+comparison/multi-URL (Steps 1b–8b). Must honor the content bar mechanically (hook **110–140**,
+length **1,200–1,800**, no body link, no banned buzzword, topic→5 pillars) and the algorithm bar
+(URL→first comment not body, post stands alone, *your reaction is the hook* not a summary,
+comment-inviting CTA, de-AI substance). **Distinct from `post`/`quick`:** the value-add is YOUR
+perspective *extending* the source, not echoing it — the commodity-reaction guard (differentiation-checker).
+
+**SIMULATE.**
+- **Persona (ICP):** the author — 1048 followers, "Validation", 5 pillars; direct/technical NO/EN voice.
+- **Invocation:** `/linkedin:react <public-sector-AI news URL>`.
+- **Walk:** Step 0 load → Step 1 single URL → Step 2 WebFetch extract → Step 3 classify (Product
+  Launch) → Step 4 angle (First-Take Analysis) → Step 5 draft (hook 110–140 ✓) → **Step 6 quality
+  check (the gap)** → Step 7 present+clipboard → Step 8 state.
+- **CONCRETE friction (spec-level, anchored — not a generated post):** at **Step 6** the quality
+  checklist (pre-edit `react.md:122–128`, 7 items) enforced hook/links/standalone/voice/charcount/
+  topic/CTA but had **no buzzword line**, so a draft opening *"This launch lets agencies leverage AI
+  to unlock synergy across the value proposition…"* passes unflagged — the banned-list (content rule
+  #4, `CLAUDE.md:124`) was never enforced at the gate. **Step 6b** (`:237` "Same as Step 6, plus")
+  inherits the hole. `react` auto-copies to clipboard (`:144–148`, no file Write) → the PreToolUse
+  **file** gate may not fire → Step 6 is the load-bearing surface. **Same gap S2 fixed in `post`.**
+- **Second friction (axis d, URL-pipeline-specific):** `grep` for fetch-failure/paywall/transcript/
+  fallback → **NONE**. Step 2 (`:54`) "Use WebFetch to extract" had **no fallback** when extraction
+  yields nothing (paywall / JS-heavy SPA / **YouTube-no-transcript** — an explicitly accepted input,
+  `:37/:71`); Step 2b (`:185`) same. Risk: proceed on a thin/empty extraction or fabricate from the URL string.
+
+**EVALUATE (4 axes).**
+- **(a) intention fidelity — PASS.** Both paths, angle selection, your-take-not-summary, commodity
+  guard, clipboard, URL→first comment — delivers the description's promise.
+- **(b) algorithm bar — PASS.** No body link (`react.md:115/125/235`); URL→first comment
+  (`:116/:144/:253`); stands alone (`:118/:126`); take-as-hook (`:101/:118`); de-AI gate bans
+  mechanical engagement-bait (`:135–137`). Consistent with `references/algorithm-signals-reference.md`.
+- **(c) MECHANICAL predicate (post-emitting) — GAP → fixed.** hook band ✓ (`:101/:124/:221`) ·
+  length band ✓ (`:119/:128/:239`) · no-body-link ✓ (`:115/:125/:235`) · topic→pillars ✓ (`:129`) ·
+  subagent resolves ✓ (`:137` → `agents/differentiation-checker.md`) · **buzzword ✗** (grep NONE; no
+  inline line in Step 6/6b).
+- **(d) agent-wiring + graceful degradation — wiring PASS; degradation GAP → fixed.** `differentiation-checker`
+  resolves, namespaced, conditional (`:137`). **Graceful degradation:** no WebFetch-failure/empty-extraction
+  fallback on EITHER path (grep NONE) — YouTube-no-transcript the sharpest, since it is a stated accepted input.
+- **Shared asset:** `quality-scorecard.md` already clean post-S2 (`110-140` at `:32/:114/:128` +
+  buzzword `:132`) — `react`'s referenced asset (`react.md:270`) is good; the gap was `react`'s OWN inline Step 6.
+
+**HARDEN (surgical — 3 edits, 1 file, all grep-confirmed landed).**
+- `commands/react.md:131` — **added** Step-6 checklist line: `- [ ] No corporate buzzwords (leverage,
+  synergy, paradigm shift, thought leader, disruptive, value proposition, ecosystem, holistic approach)`.
+  Covers Step 6b via "Same as Step 6".
+- `commands/react.md:60` — **added** Step-2 WebFetch fallback: *"If WebFetch can't extract usable
+  content (paywall / JS-heavy / YouTube-no-transcript): say so, ask the user to paste the key points
+  or choose another URL; never fabricate from the URL string or title."*
+- `commands/react.md:194` — **added** Step-2b pointer: *"If a source can't be extracted: apply the
+  Step 2 fallback — drop it if 2+ usable sources remain, else ask the user; never fabricate."*
+- **Deferrals:** none.
+- **CONCRETE after:** the "leverage…synergy…value proposition" draft now trips the Step-6 buzzword
+  line; a YouTube-no-transcript invocation now degrades to "paste the key points / pick another URL"
+  instead of a fabricated reaction.
+
+**VERIFY.**
+- `bash scripts/test-runner.sh` → `Passed: 81 · Failed: 0 · Warnings: 0`; counts **29/19/26/6** unchanged
+  (`ls commands/*.md | wc -l` == 29; `git diff --stat` = `react.md` only, +5 insertions, 0 deletions).
+- Before/after delta: axis (c) buzzword sub-check now enforced at the load-bearing Step-6 gate (both
+  paths via "Same as Step 6"); axis (d) WebFetch-failure now has a sensible fallback on both paths. The 3 edits are the cause.
+- Disposition: **HARDENED** (3 edits, axis-c + axis-d) · 0 deferrals · axes a/b PASS.
+
+---