Deals: a deal feed's stated price, retailer and end date reach the offer ("at Amazon") (#63)

ddiff --git a/README.md b/README.md
iindex 234cd39..9891097 100644
---- a/README.md
++++ b/README.md
@@@ -140,7 +140,11 @@ two subscriptions are created at boot when missing (`startSubscriptions`, needs
    facet, `noindex`) — only when it actually changed.
  - A price needs its currency: `10` without `USD` is refused (422), never completed. `$10` is refused
    (amounts are plain decimals). Imported values are copied as stated; a malformed one is `null`. A
--  price in an imported headline is **not** parsed out of the text.
++  price in an imported headline is **not** parsed out of the text. A deal feed that states its offers in its own
++  elements (Sources `feed@2`: DealNews' price with currency, retailer and end date) is a statement: the price is an
++  observation, the end date the stated end, and the retailer the offer's `seller` ("at Amazon" on cards, "Sold by" on
++  the page, `seller` in JSON and the Offer JSON-LD). The store stays the link's domain; a source whose links are kept
++  verbatim (an aggregator's own pages) never names that store after a retailer (migration `0006_offer_seller.sql`).
  - JSON-LD: `Product` with one `Offer` per offer; `price`/`priceCurrency` only from a fresh observation
    that stated both, `availability`/`itemCondition` only when stated, `validThrough` only from a stated
    end. Unknown fields are omitted, never 0 or `InStock`.
ddiff --git a/migrations/0006_offer_seller.sql b/migrations/0006_offer_seller.sql
nnew file mode 100644
iindex 0000000..088618f
---- /dev/null
++++ b/migrations/0006_offer_seller.sql
@@@ -0,0 +1,5 @@
++-- phase: expand
++-- The shop a source says sells the deal (server/domain/source-items.js): DealNews' feed names the retailer
++-- ("Amazon") while its links go to DealNews' own pages, so the store (the link's domain) is dealnews.com and the
++-- seller is kept here, exactly as stated. Null when no source named one.
++ALTER TABLE deal_offers ADD COLUMN IF NOT EXISTS seller text;
ddiff --git a/server/domain/offers.js b/server/domain/offers.js
iindex 8441ee9..a65a487 100644
---- a/server/domain/offers.js
++++ b/server/domain/offers.js
@@@ -33,9 +33,9 @@ function createOffers(deps) {
      const q = {
          byUrl: db.prepare("SELECT * FROM deal_offers WHERE url_norm = ? AND status <> 'disabled' ORDER BY created_at LIMIT 1"),
          insertOffer: db.prepare(`INSERT INTO deal_offers (id, slug, title, description, url, url_norm, store_id, product_id, category, origin, submitted_by,
--                                     text_origin, review_state, ai_summary, status, expires_at, created_at, updated_at)
++                                     text_origin, review_state, ai_summary, status, expires_at, seller, created_at, updated_at)
                                   VALUES (@id, @slug, @title, @description, @url, @url_norm, @store_id, @product_id, @category, @origin, @submitted_by,
--                                     @text_origin, @review_state, @ai_summary, 'active', @expires_at, @now, @now)`),
++                                     @text_origin, @review_state, @ai_summary, 'active', @expires_at, @seller, @now, @now)`),
          insertSource: db.prepare(`INSERT INTO deal_offer_sources (id, offer_id, kind, ref_service, ref_type, ref_id, ref_part, ref_revision, source_key, url, label,
                                        license_note, submitted_by, retrieved_at, created_at, updated_at)
                                    VALUES (@id, @offer_id, @kind, @ref_service, @ref_type, @ref_id, @ref_part, @ref_revision, @source_key, @url, @label,
@@@ -122,7 +122,7 @@ function createOffers(deps) {
              id, slug: slugify(f.title, id), title: f.title, description: f.description || null, url: f.url, url_norm: urlKey(f.url),
              store_id: f.store_id || null, product_id: f.product_id || null, category: f.category || null, origin: f.origin,
              submitted_by: f.submitted_by || null, text_origin: f.text_origin || 'human', review_state: f.review_state || 'not_required',
--            ai_summary: f.ai_summary || null, expires_at: f.expires_at == null ? null : f.expires_at, now: store.now(),
++            ai_summary: f.ai_summary || null, expires_at: f.expires_at == null ? null : f.expires_at, seller: f.seller || null, now: store.now(),
          });
          return await reads.get(id);
      }
@@@ -181,7 +181,7 @@ function createOffers(deps) {
          const offer = await insertOffer({
              title: f.title, description: f.description, url: f.url, store_id: st ? st.id : null, product_id: f.product_id || null,
              category: f.category || null, origin: 'import', submitted_by: null, text_origin: 'imported', review_state: 'pending',
--            expires_at: f.expires_at == null ? null : f.expires_at,
++            expires_at: f.expires_at == null ? null : f.expires_at, seller: f.seller || null,
          });
          const src = await ensureSource(offer.id, source);
          await hotness.snapshot(offer.id, 'create');
ddiff --git a/server/domain/publication.js b/server/domain/publication.js
iindex 20a82c9..0536dbe 100644
---- a/server/domain/publication.js
++++ b/server/domain/publication.js
@@@ -109,6 +109,8 @@ function createPublication({ config, store, reads, catalog }) {
              disabled_reason: r.status === 'disabled' ? r.disabled_reason : null,
              created_at: iso(r.created_at), updated_at: iso(r.updated_at),
              store: v.store ? { id: v.store.id, domain: v.store.domain, name: v.store.name, url: abs(storePath(v.store)) } : null,
++            // The shop a source says sells it, as stated (the store is where the link goes).
++            seller: r.seller || null,
              product: v.product ? { id: v.product.id, slug: v.product.slug, name: v.product.name, url: abs(productPath(v.product)) } : null,
              // "latest", never "current": whether it still holds is what freshness says.
              latest_observation: v.latest ? observationDto(v.latest) : null,
@@@ -135,7 +137,7 @@ function createPublication({ config, store, reads, catalog }) {
          const ld = {
              '@type': 'Offer',
              url: abs(offerPath(v.root)),
--            seller: v.store ? { '@type': 'Organization', name: v.store.name || v.store.domain } : undefined,
++            seller: v.root.seller ? { '@type': 'Organization', name: v.root.seller } : v.store ? { '@type': 'Organization', name: v.store.name || v.store.domain } : undefined,
          };
          if (fresh && o) {
              if (o.price != null && o.currency) { ld.price = o.price; ld.priceCurrency = o.currency; }
ddiff --git a/server/domain/source-items.js b/server/domain/source-items.js
iindex d7b8fce..f21e492 100644
---- a/server/domain/source-items.js
++++ b/server/domain/source-items.js
@@@ -19,7 +19,12 @@
   *                 seller → store name
   *   kind product  a product (resolved by gtin / mpn / sku / name) and one offer per stated offer
   *   kind article  (RSS/Atom) one offer with the title and link; the price is NOT parsed out of the
-- *                 headline — it stays "not stated" until a structured source or a person states it
++ *                 headline — it stays "not stated" until a structured source or a person states it. A deal
++ *                 feed's own offer elements (Sources feed@2: DealNews' price, currency, retailer and end date)
++ *                 are such a statement and map like an offer's fields.
++ *   seller        the shop the item names (fields.seller) is the offer's `seller`. It names the link's store
++ *                 too, except for a source whose links are kept verbatim (an aggregator linking its own pages:
++ *                 the store is the aggregator's domain, and the retailer must not become that store's name).
   *   other kinds   skipped
   *
   * A source policy (server/domain/source-policy.js) may require a source's links kept verbatim and
@@@ -97,10 +102,14 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
          // terms); every other source keeps today's normalisation.
          const verbatim = keepsLinksVerbatim(item.source_key);
          const linkOf = (raw) => (verbatim ? verbatimUrl(raw) : normalizeUrl(raw));
++        const sellerOf = (raw) => {
++            const seller = typeof raw === 'string' && raw.trim() ? raw.trim().slice(0, 120) : null;
++            return { seller, store_name: verbatim ? null : seller };
++        };
          if (item.kind === 'offer') {
              const url = linkOf(f.url || item.canonical_url);
              if (!url || !item.title) return [];
--            return [{ part: '', url, title: item.title, description: item.summary, obs: obsFields(f), expires_at: stated(f.valid_until), store_name: f.seller || null }];
++            return [{ part: '', url, title: item.title, description: item.summary, obs: obsFields(f), expires_at: stated(f.valid_until), ...sellerOf(f.seller) }];
          }
          if (item.kind === 'product') {
              if (!item.title) return [];
@@@ -113,7 +122,7 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
                  out.push({
                      // A verbatim source's title is used as stated, with no added words.
                      part: urlKey(url), url, title: !verbatim && o.seller ? `${item.title} — ${o.seller}` : item.title, description: item.summary,
--                    obs: obsFields(o), expires_at: stated(o.valid_until), store_name: o.seller || null,
++                    obs: obsFields(o), expires_at: stated(o.valid_until), ...sellerOf(o.seller),
                      product: { name: item.title, brand: f.brand, gtin: f.gtin, mpn: f.mpn, sku: f.sku },
                  });
              }
@@@ -122,7 +131,7 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
          if (item.kind === 'article' || item.kind === 'record') {
              const url = linkOf(item.canonical_url);
              if (!url || !item.title) return [];
--            return [{ part: '', url, title: item.title, description: item.summary, obs: obsFields({}), expires_at: null, store_name: null }];
++            return [{ part: '', url, title: item.title, description: item.summary, obs: obsFields(f), expires_at: stated(f.valid_until), ...sellerOf(f.seller) }];
          }
          return [];
      }
@@@ -171,6 +180,10 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
                  const obs = await offers.recordObservation(existing.offer_id, existing.id, c.obs, { origin, observedAt: retrievedAt, sourceRevision: item.revision });
                  const offer = await reads.get(existing.offer_id);
                  const changed = ['observation'];
++                if (origin === 'import' && c.seller && offer.origin === 'import' && c.seller !== offer.seller) {
++                    await db.prepare('UPDATE deal_offers SET seller = ?, updated_at = ? WHERE id = ?').run(c.seller, store.now(), offer.id);
++                    changed.push('seller');
++                }
                  if (origin === 'import' && c.expires_at && offer.status === 'active' && offer.origin === 'import' && c.expires_at !== offer.expires_at) {
                      await db.prepare('UPDATE deal_offers SET expires_at = ?, updated_at = ? WHERE id = ?').run(c.expires_at, store.now(), offer.id);
                      changed.push('expires_at');
@@@ -192,6 +205,7 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
                  const s = await offers.ensureSource(dup.id, src);
                  const obs = await offers.recordObservation(dup.id, s.id, c.obs, { origin: 'import', observedAt: retrievedAt, sourceRevision: item.revision });
                  if (productId && !dup.product_id) await db.prepare('UPDATE deal_offers SET product_id = ?, updated_at = ? WHERE id = ?').run(productId, store.now(), dup.id);
++                if (c.seller && !dup.seller) await db.prepare('UPDATE deal_offers SET seller = ?, updated_at = ? WHERE id = ?').run(c.seller, store.now(), dup.id);
                  await indexing.emitOffer('deals.offer.updated', await reads.get(dup.id), { actor: 'svc:deals', extra: { changed: ['sources'], observation_id: obs.id } });
                  await indexing.reindex(await reads.get(dup.id));
                  outcomes.push('attached');
@@@ -199,7 +213,7 @@ function createImporter({ config, store, reads, catalog, offers, indexing, sourc
              }
              await offers.createImported({
                  url: c.url, title: String(c.title).slice(0, 200), description: c.description, product_id: productId,
--                store_name: c.store_name, expires_at: c.expires_at != null && c.expires_at > store.now() ? c.expires_at : null,
++                store_name: c.store_name, seller: c.seller, expires_at: c.expires_at != null && c.expires_at > store.now() ? c.expires_at : null,
              }, src, c.obs, { observedAt: retrievedAt, sourceRevision: item.revision });
              outcomes.push('created');
          }
ddiff --git a/server/http/pages.js b/server/http/pages.js
iindex f2e3795..3267086 100644
---- a/server/http/pages.js
++++ b/server/http/pages.js
@@@ -181,7 +181,7 @@ function createPages(ctx) {
          const canonical = publication.abs(publication.offerPath(r));
          send(req, res, 200, {
              title: r.title,
--            description: `${views.priceText(v.latest)}${v.latest ? ` as of ${views.when(v.latest.observed_at)}` : ''}${v.store ? ` at ${v.store.name || v.store.domain}` : ''}.${r.description ? ` ${r.description.slice(0, 120)}` : ''}`,
++            description: `${views.priceText(v.latest)}${v.latest ? ` as of ${views.when(v.latest.observed_at)}` : ''}${r.seller ? ` at ${r.seller}` : v.store ? ` at ${v.store.name || v.store.domain}` : ''}.${r.description ? ` ${r.description.slice(0, 120)}` : ''}`,
              decision: v.decision,
              canonical,
              type: 'website',
@@@ -423,7 +423,7 @@ function createPages(ctx) {
              const via = v.attribution ? `Deal via ${v.attribution.text}` : null;
              return {
                  id: `deals:offer:${o.id}`, url: publication.abs(publication.offerPath(o)), title: o.title,
--                summary: `${via ? `${via}. ` : ''}${price}${v.store ? ` at ${v.store.name || v.store.domain}` : ''}.${o.description ? ` ${o.description.slice(0, 300)}` : ''}`,
++                summary: `${via ? `${via}. ` : ''}${price}${v.root.seller ? ` at ${v.root.seller}` : v.store ? ` at ${v.store.name || v.store.domain}` : ''}.${o.description ? ` ${o.description.slice(0, 300)}` : ''}`,
                  tags: via ? [via] : undefined,
                  published: o.created_at, updated: Math.max(o.updated_at, v.latest ? v.latest.observed_at : 0), decision: v.decision,
              };
ddiff --git a/server/render/views.js b/server/render/views.js
iindex e3908df..41782e4 100644
---- a/server/render/views.js
++++ b/server/render/views.js
@@@ -84,7 +84,7 @@ function offerCard(v, urls) {
  <h2 class="deal-title"><a href="${urls.offerPath(r)}">${r.title}</a> ${statusBadge(r)}</h2>
  ${latestLine(v)}
  ${attributionLine(v.attribution)}
--<p class="meta">${v.store ? html`<a href="${urls.storePath(v.store)}">${v.store.name || v.store.domain}</a> · ` : ''}${v.product ? html`<a href="${urls.productPath(v.product)}">${v.product.name}</a> · ` : ''}posted ${timeEl(r.created_at)}${r.origin === 'import' ? ' · imported from a source' : ''}</p>
++<p class="meta">${r.seller ? html`<span class="seller">at ${r.seller}</span> · ` : ''}${v.store ? html`<a href="${urls.storePath(v.store)}">${v.store.name || v.store.domain}</a> · ` : ''}${v.product ? html`<a href="${urls.productPath(v.product)}">${v.product.name}</a> · ` : ''}posted ${timeEl(r.created_at)}${r.origin === 'import' ? ' · imported from a source' : ''}</p>
  </div></li>`;
  }
  
@@@ -176,7 +176,8 @@ ${r.description ? html`<section class="description">${raw(renderMarkdown(r.descr
  ${r.ai_summary ? html`<section class="disclosure"><p><strong>AI-assisted summary</strong>${r.review_state === 'reviewed' ? ' (reviewed by a person)' : ' (not yet reviewed by a person)'}</p><p>${r.ai_summary}</p></section>` : ''}
  ${r.review_state === 'pending' && r.text_origin === 'imported' ? html`<p class="disclosure">This deal was imported from a source and has not been reviewed by a person yet.</p>` : ''}
  <dl class="facts">
--<dt>Store</dt><dd>${v.store ? html`<a href="${urls.storePath(v.store)}">${v.store.name || v.store.domain}</a>` : 'not stated'}</dd>
++${r.seller ? html`<dt>Sold by</dt><dd>${r.seller} <span class="meta">(as the source states it)</span></dd>` : ''}
++<dt>${r.seller ? 'Link goes to' : 'Store'}</dt><dd>${v.store ? html`<a href="${urls.storePath(v.store)}">${v.store.name || v.store.domain}</a>` : 'not stated'}</dd>
  <dt>Product</dt><dd>${v.product ? html`<a href="${urls.productPath(v.product)}">${v.product.name}</a>` : 'not linked'}</dd>
  <dt>Posted</dt><dd>${timeEl(r.created_at)} ${r.origin === 'import' ? '(imported)' : '(by a member)'}</dd>
  </dl>
@@@ -222,7 +223,7 @@ function productPage({ pv, urls }) {
      const p = pv.product;
      const rows = pv.offers.map((v) => html`<tr>
  <td><a href="${urls.offerPath(v.root)}">${v.root.title}</a> ${statusBadge(v.root)}${attributionLine(v.attribution)}</td>
--<td>${v.store ? v.store.name || v.store.domain : 'not stated'}</td>
++<td>${v.root.seller || (v.store ? v.store.name || v.store.domain : 'not stated')}</td>
  <td data-price="${v.latest && v.latest.price != null ? v.latest.price : ''}">${priceText(v.latest)}${v.latest && shippingText(v.latest) ? html` <span class="meta">${shippingText(v.latest)}</span>` : ''}</td>
  <td>${v.latest ? timeEl(v.latest.observed_at) : html`<span class="meta">never observed</span>`}</td>
  <td>${freshnessBadge(v.freshness, v.now)}</td>
ddiff --git a/test/import.test.js b/test/import.test.js
iindex ba564e9..c8a79a2 100644
---- a/test/import.test.js
++++ b/test/import.test.js
@@@ -179,6 +179,35 @@ const { signDelivery, signDeliveryHeaders } = require('openvibe-sdk/events');
          assert.deepStrictEqual(normal.json().offer.attribution, { text: 'DealNews', url: 'https://www.dealnews.com/' });
      });
  
++    await check('a deal feed\'s stated price, retailer and end date (Sources feed@2): on the offer; the retailer never names the aggregator\'s store', async () => {
++        const link = 'https://www.dealnews.com/products/Vosser/Air-Mattress/508347.html?iref=rss';
++        const ends = t.clock.now() + 30 * 86400000;
++        t.sources.put(sourceItem({ id: 'itm_01K5AAAAAAAAAAAAAAAAAAAAB1', sourceKey: 'dealnews-daily', kind: 'article', title: 'Vosser Queen Air Mattress for $67 + free shipping', url: link,
++            fields: { categories: [], price: '67.00', currency: 'USD', seller: 'Amazon', valid_until: new Date(ends).toISOString() }, retrievedAt: t.clock.now() }));
++        t.sources.put(sourceItem({ id: 'itm_01K5AAAAAAAAAAAAAAAAAAAAB2', sourceKey: 'dealnews-daily', kind: 'article', title: 'Target sale', url: 'https://www.dealnews.com/target-sale/1.html',
++            fields: { seller: 'Target' }, retrievedAt: t.clock.now() }));
++        const s = await t.ctx.importer.pull();
++        assert.deepStrictEqual(s.outcomes, { created: 2 }, JSON.stringify(s));
++        const offer = await byUrl(link);
++        assert.strictEqual(offer.seller, 'Amazon');
++        assert.strictEqual(offer.expires_at, ends, 'the stated end date');
++        const json = await t.offerJson(offer.slug);
++        assert.deepStrictEqual([json.latest_observation.price, json.latest_observation.currency, json.seller, json.store.domain, json.store.name], ['67.00', 'USD', 'Amazon', 'dealnews.com', null],
++            'the price as stated; the store stays dealnews.com, unnamed (a retailer must not become the aggregator\'s name)');
++        const target = await byUrl('https://www.dealnews.com/target-sale/1.html');
++        assert.deepStrictEqual([target.seller, (await t.offerJson(target.slug)).latest_observation.price], ['Target', null], 'no stated price stays not stated');
++        const page = await t.get(`/d/${offer.slug}`);
++        assert.ok(page.text.includes('<dt>Sold by</dt><dd>Amazon') && page.text.includes('<dt>Link goes to</dt>'), 'the page says who sells it and where the link goes');
++        assert.ok((await t.get('/new')).text.includes('<span class="seller">at Amazon</span>'), 'the card names the seller');
++        assert.match((await t.get('/feed.xml')).text, /at Amazon\./);
++        // A later revision naming another retailer updates the offer's seller.
++        t.sources.put(sourceItem({ id: 'itm_01K5AAAAAAAAAAAAAAAAAAAAB2', sourceKey: 'dealnews-daily', kind: 'article', title: 'Target sale', url: 'https://www.dealnews.com/target-sale/1.html',
++            fields: { seller: 'Target.com', price: '10.00', currency: 'USD' }, revision: 2, retrievedAt: t.clock.now() + 1000 }));
++        await t.ctx.importer.pull();
++        const again = await byUrl('https://www.dealnews.com/target-sale/1.html');
++        assert.deepStrictEqual([again.seller, (await t.offerJson(again.slug)).latest_observation.price], ['Target.com', '10.00']);
++    });
++
      await check('Sources down: the pull fails honestly (readiness says so), keeps its cursor, invents nothing', async () => {
          const cursor = await t.ctx.importer.cursor();
          const offers = (await t.ctx.store.db.prepare('SELECT COUNT(*) AS n FROM deal_offers').get()).n;