Post Writer

### Added (the ARTICLE form — the headline scope)
post-writer shipped ten recipes through 1.5.4 and **every one was a post**. There was no LinkedIn Article recipe and no X Article recipe in this skill or any sibling. Because the recipe did not exist, the 2026-08-22 `@di-atomic/outbound-engine` launch run had to invent the process live and burned **six drafts** converging 2,894w → 1,440 → 1,306 → 1,459 → 1,592 → **850w**. That churn is the cost of the missing recipe.
- **`recipes/linkedin-article.md`** — the LinkedIn Article **surface**: structure, length, CTA, media specs (cover 1920×1080 16:9; ⚠ 1200×627 is the share-preview card and 2000×600 is a stale cached spec — LinkedIn Help `a521719`/`a522472`), and publishing mechanics (**desktop/tablet web only, no mobile editor**; not in the vibe-publish → Blotato path — a human pastes it). Images upload direct to LinkedIn, so **no SpiderMedia round-trip**.
- **`recipes/x-article.md`** — built from the 13 `x-*` registry items + the thread recipe. ⚠ **We own no measured X corpus** (every Di-Atomic corpus is LinkedIn: 83 / 164 / 328). Every length and CTA number in it is stamped an **untested hypothesis with its provenance stated in-file**, and no LinkedIn number is carried across. Emits `evidence_class: "hypothesis"`. Defaults back to a thread.
- **`references/post-structures-by-platform.md` § "The ARTICLE form"** — specs for both surfaces + the CTA rule, and an explicit statement that **`verify-post-structure.mjs` does NOT grade articles**: it enforces post bands (LinkedIn 3,000-char ceiling, X single 71–100 chars), so an 850-word article FAILs on length for the wrong reason, and "fixing" it to pass destroys the piece.
- **3 learnings** — `2026-08-24-the-article-is-a-different-artifact` · `-dm-is-the-conversion-event` · `-length-bands-are-topic-scoped`.
- **`scripts/verify-article-cta.mjs`** (5th enforcement script) — **makes the CTA lock enforceable instead of advisory.** Found during testing: `verify-post-structure.mjs` counts CTA *classes*, so a comment-gate and a DM ask are both "1 engagement CTA" — it scores the worked example's `Comment **outbound** and I will send you mine` as **PASS**. The locked rule was a rule no script could see. The new script separates codeword bait from a plain comment solicitation from a conversion ask, takes `--pillar icp|practitioner|export-teaching` so the Pillar-3 exception is a flag rather than a judgement call, and prints `gate_hits` / `solicit_hits` / `dm` / `link`. Proved on **8 committed fixtures** in both directions (`tests/fixtures/article-cta/`): codeword-shout, codeword-lowercase-emphasised and type-BELOW all FAIL; a narrative mention of "the comments" PASSes (no false positive); a piece with no conversion event at all FAILs; Pillar 3 carrying **both** asks PASSes under the exception and FAILs under `icp`.

### Changed (CTA — 🔒 locked by Martin 2026-08-24)
- **On an ICP-pillar piece the conversion event is a DM, never a comment-gate.** This overrides the comment-gate design of `AP-71`/`AP-74`, **including the closing line of the worked example** — the recipe says so explicitly so nobody copies it. Evidence: 328 posts / 12 queries / 299 authors. Compliance corpus median **0 comments** (68% zero, comment:like **0.000**); buyer-language 1 (42% zero, 0.057); practitioner 15 (0.42). The audience **reads** — buyer-language out-reads compliance and approaches practitioner reach; only *public* engagement collapses, structurally: commenting on a regulatory post reads as giving regulatory advice. The gate cannot be baited into existence either — it appears **2 of 151** and **5 of 177**.
- **`≤1 CTA PER CLASS` is unchanged** — only the *choice* of engagement ask moved. One named exception: **Pillar 3 export-teaching** (Paresh Solanki, 3 posts at 58/42/29 comments), the only measured case of an ICP-adjacent topic earning real comments from an ICP-adjacent audience. Named, not generalised.
- **Success = connection requests + DM replies + profile views.** Comments demote to a *health* signal. ⚠ Counting is **manual** — LinkedIn exposes no clean personal-profile API read. The bar is set **per topic**: a compliance post at 3 comments is top 12% of its own topic space.

### Changed (length bands — re-sourced, not swapped)
- **The "viral length sweet spot ~600–1,000 chars" is DEMOTED to a starting hypothesis.** It came from a single creator and was written down as a platform constant. The 164-post corpus measured on our own topic found that exact bucket **worst-performing** (median comments: 0–600 → 9 · **600–1,000 → 8** · 1,000–1,500 → **17** · 1,500–2,200 → 15 · 2,200+ → **19**; top organic post **2,985 chars**).
- **Neither number is adopted as the answer.** Acosta is n=1 creator (personal-brand narrative); outbound is n=1 topic (B2B practitioner). The defect was a single-source band presented as a constant — swapping in another single-source band repeats it. The rule is now **measure the topic, not the platform**, and the enforced band stays deliberately wide at 600–2,100 (WARN outside; FAIL <500 or >3,000 — the verifier was already right; only the prose over-claimed). Two things hold across both corpora: **≥500 chars** (AuthoredUp 372k-post study) and **a digit in the hook** (2.2×, n=143 organic).
- Article band recorded as what it is: **800–1,200 words is a six-draft convergence on a piece that was never published**, not an engagement measurement.

### Changed (the three shallow story items → cross-references)
`linkedin-hook-story-engage-cta` (four bullets), `linkedin-career-arc-story` and `linkedin-personal-vulnerability` now **cross-reference `@di-atomic/copy-engine@>=0.6.3` for the story METHOD** (`registry/epiphany-bridge-script` · `heros-two-journeys` · `narrative-voice-bars` · `recipes/story-led-article.md`) and keep only the genuinely platform-specific residue: the ≤140-char fold, beat density, no-mechanics mode, and the CTA class. Each grew from 17 lines to 39–48. Item versions → 1.1.0.

### Fixed (self-miscounts — every number below was generated, not typed)
- `SKILL.md` frontmatter said **`version: 1.5.0`** while the package was 1.5.4.
- **"68 exemplars" → 74** (SKILL.md ×2, README ×2, AGENTS.md). The registry has carried 74 since 1.5.4.
- **"3 scripts" → 4** (SKILL.md ×3, README ×2, AGENTS.md, schema.yaml, package.yaml marketing). `verify-coordination` was never counted.
- **"38-entry AI-slop blacklist" → 55** in the marketplace feature copy. The list grew; the claim did not.
- **"Nine recipes" → eleven** in the marketplace feature copy.
- **Provenance drift on the two story items:** their 1.5.4 LOW → HIGH upgrade (earned on the Acosta corpus — *"pov: you become the first millionaire in your family"* 4,452 likes/1,389 comments; *"Age 18: Couldn't speak in public"* 3,530/1,761) landed in `registry-item.json` and `registry.json` but **never in `pattern.md`**, which still read LOW and still cited only the weak original sources (qualitative / self-reported). The prose now carries the upgrade *and* both sources, marked for what each is. Verified 0 confidence mismatches across item / index / prose across all 74 items.

### Changed (peers)
- **`@di-atomic/copy-engine` floor `>=0.4.1` → `>=0.6.3`.** The article recipes and the three story items cross-reference registry items that do not exist below 0.6.3.

### Not in this release
- **TikTok / Pinterest / Bluesky** — retargeted to 1.7.0. Additive registry work; shipping it alongside a new artifact form would bury the form.
- **The end-to-end production run recipe** (signal → source → story → draft → gate → media → publish → measure) — belongs to `@di-atomic/social-media-manager`.
- **Media** unchanged: 1.6.0 preserves the 1.5.4 hero + 3 screenshots.

### Changed (LinkedIn model rebuilt on real top-performer evidence)
Grounded in an 83-post corpus of Lara Acosta (349K followers, sells LinkedIn growth), pulled via `scrapecreators /v1/linkedin/search/posts`. Her data overturned three of our LinkedIn assumptions — all fixed here, and her top 5 posts now PASS the verifier where they FAILed before.
- **LinkedIn length band: optimal-lo 1,300 → 600.** Her viral sweet spot is ~600–1,000 chars (median winner 945), not the 1,300–2,100 a generic tool assumes. Floor stays 500 (her <600 posts underperform). `verify-post-structure.mjs` + `references/post-structures-by-platform.md` updated.
- **CTA rule: split into engagement + conversion classes, ≤1 EACH** (was ≤1 total). Her proven two-position pattern — an engagement ask (repost/comment) in the body + a conversion link in a trailing `PS:` — appears in 11 of her top 20 and used to FAIL our counter. Now `1 engage + 1 convert` passes; two of the same class still FAILs (choice-overload intact). The counter now scans only the **closing zone** (PS + last 3 lines + URL lines) so narrative mentions of "comment"/"share" no longer false-positive.
- **Story beats tactic — angle guidance rewritten.** Her top 3 posts are first-person narrative (dad picking cotton 4,452L; Forbes 30U30 3,869L; her stutter 3,530L); half her top-20 hooks are confessions, one is a listicle-promise. `recipes/linkedin-post.md` now leads with the story modes; `linkedin-personal-vulnerability` + `linkedin-career-arc-story` upgraded **LOW → HIGH** with her real metrics. Visual reframed as the default (carousel 2,046 > image 1,773 > text 1,248 median likes), not an optional step.
### Added
- **New registry item** `linkedin-two-position-cta` (HIGH) — the engage-ask + PS-link pattern, with her verbatim examples. Registry now 74 items (38 HIGH).
- **Learning** `2026-07-26-linkedin-story-beats-tactic` — the full corpus evidence: what it overturned, what it confirmed (hooks ≤60c, comment-optimized, 0 em-dashes, Flesch ~71), format-vs-virality and length-vs-virality tables.
### Fixed
- **scrapecreators-api SKILL.md** (separate skill, corrected in passing during the YouTube sweep): `/v1/youtube/channel/videos` → `/v1/youtube/channel-videos` (the old path 404s); removed the phantom `/v1/credit/balance` (404s — `credits_remaining` is inline on every response).

### Added
- **Two new platform recipes.** `recipes/youtube-description.md` — YouTube title + description, built on a 20-video scrapecreators sweep of 5 creators. Encodes the **discovery vs authority mode** split (SEO-surface vs credential-wall — pick first, they are opposites), the ~157-char fold strategy, keyword-titled chapters (first must be `0:00`, ≥3), the free-asset→community→paid value ladder, and mandatory affiliate disclosure. `recipes/reddit-post.md` — **advise-only** by design: reads the subreddit's norms first (via scrapecreators), drafts to a board card, and the human posts it from their own account. No auto-post (Reddit has no publish API in the stack, and that constraint is correct). Human-shaped prose by **stripping AI tells, never faking errors**; hard disclosure rule for self-promo; also documents Reddit as a research surface feeding copy-engine / community / social-media-manager.
- **5 evidence-backed YouTube registry items** — `youtube-fold-keyword-first` · `youtube-fold-money-link` · `youtube-funnel-ladder` · `youtube-withhold-to-paid` · `youtube-authority-wall`, each with verbatim provenance from the creator sweep. Registry now 73 items.
- **Learning** `2026-07-22-youtube-description-two-modes` — the discovery/authority evidence with real quotes from Wolfe / NetworkChuck / Jack / nateherk / Hormozi.
### Changed
- **`verify-post-structure.mjs`** gained `youtube` + `reddit` body bands (+ `yt`/`sub`/`subreddit` aliases). Both grade the BODY only — YouTube title and Reddit title are separate fields no script checks; the recipes carry those rules inline. SKILL.md router now lists 9 platforms; `references/post-structures-by-platform.md` gained both rows + the title/body caveat.
### Fixed
- **Visibility fixed to `public`.** 1.5.1 and 1.5.2 shipped `skills[0].visibility: internal` while `tier: beta` — which means they were **uninstallable** (customer-invisible) despite the card reading shipped. 1.5.3 is the first actually-installable release since the nested migration. Caught by `verify-packaging.mjs`.
- **`schema.yaml` coordination mirror restored.** The 1.5.1 nested migration dropped the `guidance.uses:` block, so `verify-coordination.mjs` had been FAILing since 1.5.1 (it is not in the publish gate, so 1.5.1 and 1.5.2 shipped over it). Re-added, mirroring the SKILL.md `## Coordination` section. Now PASS.

### Fixed
- **Package description corrected.** It still advertised `v1.4.0: GUIDANCE-ONLY shape (skills:[] + peer_dependencies)` — the exact shape 1.5.1 removed. Reworded to describe the nested `skills/post-writer/` layout that `skill_read` actually resolves. Docs-only patch; no code, guidance or manifest-structure change.

### Fixed
- **Bundle shape corrected to the nested guidance-only layout.** 1.5.0 and earlier shipped `skills: []` with a root `SKILL.md`, which is the 2026-06-17 regression: `skill_read` resolves `SKILL.md` from the schema dir, so a root-only `SKILL.md` 404s and agents could not read the guidance they installed. Now ships `skills: [{id: post-writer, schema: ./skills/post-writer/schema.yaml}]` with `SKILL.md` + `references/` + `recipes/` + `registry/` + `learnings/` + `scripts/` + `instructions/` + `source/` relocated under `skills/post-writer/`. `docs.skill_guide` repointed. `verify-packaging.mjs` now PASSes (6 pass · 0 fail) where 1.5.0 shipped on an explicit gate bypass.
- Added `skills/post-writer/schema.yaml` — guidance-only (no `methods:` block), carrying the use/not/chains/limits/pitfalls/case_study guidance and the four conceptual operations.
### Added
- **Marketplace card asset kit (SPEC-3).** Top-level `media:` block with a hero and three panel screenshots in the Di-Atomic dark-board chalk style (`#131313` board / white chalk / gold `#EEBF01`), rendered via `kie/nano-banana-2` through SpiderGate and persisted to SpiderMedia.
- **`marketing:` block** — first-person 150-200 word long description plus five verb-led feature bullets with icons. The card was previously bare (`media.screenshots: []`, `marketing.features: []`).
- No guidance, recipe, registry or script content changed in this release. Behaviour is identical to 1.5.0; only the packaging shape and the card metadata moved.

### Added (cross-analysis wave — absorbed from @di-atomic/skill-blog-post's 2026 research)
- **3 learnings.** `2026-07-19-name-an-enemy-behavior` (the enemy-first opener — independently validated across r/copywriting + Empire Writer, connected to the existing `x-launch-post-forensics` pain-naming gate; enemy must be a *behavior*, never a competitor) · `2026-07-19-first-line-earns-the-next` (curiosity-loop momentum — the first line only has to earn the second) · `2026-07-19-spiderpublish-body-is-markdown-now` (the corrected SpiderPublish handoff).
- **`references/algo-2026.md`** — added "Name an enemy (behavior, not competitor)" to cross-platform constants, linked to both new opener learnings.
### Changed (corrections — the SpiderPublish handoff was stale)
- **`references/publishing-targets.md`** refreshed from a hands-on probe of the live Di-Atomic tenant (2026-07-19): (1) blog body is now sent as `{markdown}` — the server normalizes to Tiptap since 2026-07-09; the old "convert prose → Tiptap / a string renders empty" rule is superseded; (2) Di-Atomic tenant tags are legacy STRING tags, not `tag_ids` (the entity table is empty); (3) added the `cover_image_url` host-allowlist + `media_ingest_url` fallback (files.opvs.ai blocked); (4) added the mandatory agent-browser render-verify gate; (5) added the fixed author/category IDs. Handoff contract block updated (`body_markdown` + string `tags`).
- Additive minor bump — no recipe/router/script restructure; all prior guidance preserved.

### Changed
- **Converted to the canonical GUIDANCE-ONLY shape** (OPVS spec locked 2026-06-17). post-writer doesn't DO anything — the agent's own LLM composes posts from `SKILL.md` + bundled references/recipes/registry/learnings + local verifier scripts. Accessed via the `skill_read` substrate tool.
  - `skills: []` (was a single phantom-method skill entry).
  - Removed `client/schema.yaml` from the bundle (it declared an HTTP `base_url` that 404s at runtime) → moved to `source/legacy/client-v1.3.0/` for provenance.
  - `peer_dependencies` now declares the 4 upstream OPVS coordination skills (agentdocs/agentboard/agentmemory/opvs-protocol) + the `@di-atomic` siblings post-writer composes with (voice-builder, hook-generator, copy-engine), at live marketplace version ranges.
  - `docs` block fixed: `readme` (marketplace listing) + `skill_guide` (what `skill_read` returns) + `changelog`.
  - Added `README.md` + this `CHANGELOG.md` at bundle root.
- **verify-coordination.mjs** now imports the vendored shared helper (`./_verify-coordination-shared.mjs`) — the shipped variant; PASS.

### Added
- **v2.2 Coordination cross-references** — `## Coordination` section in SKILL.md declaring all 4 OPVS surfaces (all USE) + `verify-coordination.mjs` enforcement + BRIEF §0/§3.8.

### Added
- **SpiderMedia awareness** — host images/videos/PDFs on the CDN (`media.cdn.spideriq.ai`) before referencing; `references/publishing-targets.md` media section + learning.

### Added
- **SpiderPublish awareness** — owned-site host (blog/news/docs/pages/forms) routing vs vibe-publish (social); `references/publishing-targets.md` + learning.

### Added
- Initial 7-layer v2.1 build: SKILL.md router · 4 references · 7 recipes · 13 learnings · 68 metric-bearing registry exemplars · 3 enforcement scripts · source provenance. 13/13 tests PASS, 100/100 security score.