Add docs/MIGRATION.md for adopting each release and point README to it

ddiff --git a/README.md b/README.md
iindex 0c5e5fd..f86c72a 100644
---- a/README.md
++++ b/README.md
@@@ -177,21 +177,9 @@ order).
  **Tests.** `createDb({ pglite: true })`, then `await store.ensureSchema()` (or `db.migrate({ dir })`
  with the product's migrations): real PostgreSQL in-process.
  
--## Moving a product from 0.4 to 1.0
--
--Mostly mechanical; [CHANGELOG.md](CHANGELOG.md) lists every change. In short:
--
--1. Pin `openvibe-publishing` v1.0.0, `openvibe-sdk` v0.15.0 and `pg`; `@electric-sql/pglite` for tests.
--2. Put `publishing.schema({ … })` for the stores and prefixes the product uses into its
--   `migrations/0001_initial.sql` (with its own tables), so the SDK's `importSqlite` finds every table
--   when it moves the SQLite data.
--3. Pass the `openvibe-sdk/db` handle instead of the better-sqlite3 one, and `await` every store call.
--4. Replace `db.transaction(() => { … })()` around store calls with `await db.tx(async (t) => { … })`
--   and pass `t` as the first argument of every store call inside it.
--5. Beyond `await`: `stamp(t, doc)` takes the handle first; `redirects.resolve()`'s `currentPath`
--   may be async (and should be); rows come back with parsed JSON (`fields`, `meta`, `ref`, `result`)
--   exactly as the store shapes already returned them; list methods cap at their `limit`; loops of
--   per-item reads in list routes become the batch reads above.
++## Moving a product between releases
++
++See [docs/MIGRATION.md](docs/MIGRATION.md): 0.4 → 1.0, 1.0 → 1.1 and 1.1 → 1.2, step by step.
  
  ## The indexability gate
  
ddiff --git a/docs/MIGRATION.md b/docs/MIGRATION.md
nnew file mode 100644
iindex 0000000..36579e9
---- /dev/null
++++ b/docs/MIGRATION.md
@@@ -0,0 +1,83 @@
++# Adopting a Publishing release
++
++How a content product (Blog, Coupons, Deals, News, Reviews, Trade, Wiki) moves to each
++`openvibe-publishing` release. [CHANGELOG.md](../CHANGELOG.md) lists every change; this page is the
++order of work. One section per step; do them in order.
++
++Rules that hold for every step:
++
++- **Pin the release tarball**, never a `file:` link or a vendored copy:
++  `"openvibe-publishing": "https://codeload.github.com/OpenVibers/OpenVibe.Publishing/tar.gz/refs/tags/vX.Y.Z"`.
++- **Lockfile:** copy the `node_modules/openvibe-publishing` entry (`version`, `resolved`, `integrity`)
++  from a product already on that tag. Never leave `integrity` empty and never write one by hand; if no
++  product is on the tag yet, run the install in the product's own pipeline so npm computes it.
++- Every release is additive; a product only changes what its section lists.
++
++## v0.4 → v1.0.0
++
++Mostly mechanical:
++
++1. Pin `openvibe-publishing` v1.0.0, `openvibe-sdk` v0.15.0 and `pg`; `@electric-sql/pglite` for tests.
++2. Put `publishing.schema({ … })` for the stores and prefixes the product uses into its
++   `migrations/0001_initial.sql` (with its own tables), so the SDK's `importSqlite` finds every table
++   when it moves the SQLite data.
++3. Pass the `openvibe-sdk/db` handle instead of the better-sqlite3 one, and `await` every store call.
++4. Replace `db.transaction(() => { … })()` around store calls with `await db.tx(async (t) => { … })`
++   and pass `t` as the first argument of every store call inside it.
++5. Beyond `await`: `stamp(t, doc)` takes the handle first; `redirects.resolve()`'s `currentPath`
++   may be async (and should be); rows come back with parsed JSON (`fields`, `meta`, `ref`, `result`)
++   exactly as the store shapes already returned them; list methods cap at their `limit`; loops of
++   per-item reads in list routes become the batch reads in the README ("Lists are bounded").
++
++## v1.0.0 → v1.1.0
++
++Adds `openvibe-publishing/ingest` and `openvibe-publishing/publication`; nothing existing changes.
++The five content products (News, Reviews, Deals, Coupons, Trade) each delete their own copy of this code.
++
++- **package.json:** `"openvibe-publishing": "https://codeload.github.com/OpenVibers/OpenVibe.Publishing/tar.gz/refs/tags/v1.1.0"`.
++- **Lockfile:** copy the entry from a product already on v1.1.0 (or later, then take that product's
++  v1.1.0 history); `version` `1.1.0`, the matching `resolved` URL, the real `integrity`.
++- **Require lines:**
++  ```js
++  const ingest = require('openvibe-publishing/ingest');           // Sources client, change cursor, pullChanges, event consumer, normalisers, PSL
++  const { createPublication } = require('openvibe-publishing/publication');  // gate → document → stamp → events → outbox, IndexNow ping
++  ```
++  The ingest cursor's table comes from the product's migrations: `publishing.schema({ ingest: … })`
++  (`<prefix>_ingest_cursor`); the runtime role cannot create tables.
++- **Files to delete** (the product-local copies named in `lib/publication.js`'s header):
++  News `domain/publication.js`, Reviews `service.js` (the publication part), Deals `domain/indexing.js`,
++  Coupons `domain/publication.js`, Trade `domain/indexing.js`; plus the product's private Sources
++  client, change-cursor loop, signed-event inbox and normalisers that `openvibe-publishing/ingest` now
++  provides. What stays per product: the gate facts, facets, the document body and the domain tables.
++  Delete a file only once its callers use the shared module.
++- **Test:** the product's own suite (`ov test`), including its ingest and publication tests; the
++  Publishing side is `test/ingest.test.js` and `test/publication.test.js`.
++
++## v1.1.0 → v1.2.0
++
++Adds `openvibe-publishing/layout`; nothing existing changes. The seven publication sites each hand-wrote
++the page document; `renderDocument` replaces that, composed over `openvibe-shared/shell` `page()`.
++
++- **package.json:** pin `openvibe-publishing` at `…/refs/tags/v1.2.0` **and** `openvibe-shared` at
++  `https://codeload.github.com/OpenVibers/OpenVibe.Shared/tar.gz/refs/tags/v2.6.0`. `layout` requires
++  `openvibe-shared/shell`, which exists only from Shared v2.6.0; the other entry points keep the
++  `>=1.5.0` peer range, so an older Shared fails only on `require('openvibe-publishing/layout')`.
++- **Lockfile:** copy both the `node_modules/openvibe-publishing` (1.2.0) and
++  `node_modules/openvibe-shared` (2.6.0) entries from a product already on those tags
++  (OpenVibe.News main). Never an empty or invented `integrity`.
++- **Require line:** `const layout = require('openvibe-publishing/layout');`
++- **What views call:** `layout.renderDocument({ site, siteName, title, description, canonical, decision,
++  jsonLd, feeds, navbar, footer, navLinks, css, release, account, body, … })` and send the string.
++  - `decision` is the gate's decision and is the robots source (`decision.robots`; canonical is
++    `decision.canonical || canonical`). Without a decision (or an explicit `robots` string) it throws
++    `TypeError`: no page is indexable by default.
++  - `title` is composed by the caller; `body` is the `<main>` HTML; `css`, `scripts`, `head`, `header`,
++    `account`, `body`, `shipped` are trusted markup the caller built; everything else is escaped.
++  - It adds the head extras, the body frame (skip link, `#navbar-mount`, `<main>`) and the footer init
++    the shell never emits. Styling is unchanged.
++- **Files to delete:** the product's hand-written document/layout function body (its `<html>…</html>`
++  template, head tags, skip link, footer init); keep a thin wrapper that builds the navbar/footer config
++  and calls `renderDocument`.
++- **Worked example:** OpenVibe.News main, `server/render/layout.js` (`renderPage` builds `nav`,
++  `footer`, `account` and returns `layout.renderDocument({ site: 'news', … })`), landed in News PR #6.
++- **Test:** the product's page/render tests (`ov test`); Publishing's side is `test/layout.test.js`.