Inventory: tell search engines about new and changed item pages (IndexNow) (#48)

ddiff --git a/.env.example b/.env.example
iindex 44878ac..7d50c51 100644
---- a/.env.example
++++ b/.env.example
@@@ -4,6 +4,9 @@ NODE_ENV=production
  PORT=5030
  HOST=127.0.0.1
  BASE_URL=https://inventory.openvibe.network
++# IndexNow: with a key (8–128 letters and digits), pages Search gains or changes are sent to search engines and the
++# key is served at /<key>.txt. Unset: off.
++#INDEXNOW_KEY=
  TRUST_PROXY=2
  # PostgreSQL (ADR-035), written by OpenVibe.Host roles/data/add-service.sh inventory: the runtime role through PgBouncer,
  # the owner on a direct connection (migrations), and Valkey (shared limit counters).
ddiff --git a/README.md b/README.md
iindex 5522dcb..c3758d8 100644
---- a/README.md
++++ b/README.md
@@@ -128,7 +128,8 @@ them.
  
  `/` (what it is), `/items` (every item by kind), `/items/:id` (one item: where it shows, who gives it, how many exist),
  `/me` (your items; Wear and Take off are plain forms), `/u/:subject` (a person's public inventory) and `/updates`.
--Every page works without JavaScript.
++Every page works without JavaScript. With `INDEXNOW_KEY`, each item page Search gains or changes is sent to search
++engines (IndexNow, through `openvibe-publishing/search-feed`) and the key is served at `/<key>.txt`.
  
  ## Moving Live's cosmetics (ADR-054 §8)
  
ddiff --git a/server/app.js b/server/app.js
iindex d60dac8..34eb39d 100644
---- a/server/app.js
++++ b/server/app.js
@@@ -35,6 +35,7 @@ const { createServiceReadiness } = require('./observability');
  const { createCallerLimits } = require('./http/caller-limits');
  const { createServiceOutbox } = require('openvibe-sdk/events');
  const { createSearchIndex } = require('./search-index');
++const { createIndexNow } = require('openvibe-shared/indexnow');
  const { createNetworkSender } = require('openvibe-sdk/account-data');
  const { createInventory } = require('./inventory/store');
  const { seed } = require('./inventory/seed');
@@@ -69,7 +70,15 @@ async function createApp(opts = {}) {
      await seed(inv, { log });
      // Item pages in OpenVibe.Search (./search-index.js) through the same outbox: the definition writes name what they
      // changed (watch), and a sweep runs on its own timer once server/index.js starts it.
--    const searchIndex = opts.searchIndex || createSearchIndex({ config, s, outbox, log });
++    // IndexNow: off without INDEXNOW_KEY; a malformed key warns and stays off rather than stopping the site.
++    const indexnow = opts.indexnow || (() => {
++        const warn = (...a) => (log.warn || console.warn)(...a);
++        try { return createIndexNow({ host: config.baseUrl, key: config.indexnow.key, fetch: fetchImpl, log: warn }); } catch (err) {
++            warn(`[Inventory] ${err.message} — IndexNow is off until INDEXNOW_KEY is fixed`);
++            return createIndexNow({ host: config.baseUrl, key: '', fetch: fetchImpl, log: warn });
++        }
++    })();
++    const searchIndex = opts.searchIndex || createSearchIndex({ config, s, outbox, log, indexnow });
      searchIndex.watch(inv);
      // Account export and deletion (ADR-033): the table map, and the sender to Network's internal routes with this
      // service's own client-credentials token.
@@@ -140,6 +149,8 @@ async function createApp(opts = {}) {
  
      // ── Static assets (content-hashed ?v= → immutable) ──────
      app.use('/shared', require('openvibe-shared/serve').handler());
++    // GET /<key>.txt — the IndexNow key file, only when a key is configured.
++    if (indexnow.enabled) app.use(indexnow.keyFile);
      app.use(express.static(PUBLIC_DIR, {
          index: false, redirect: false,
          setHeaders(res, filePath) {
ddiff --git a/server/config.js b/server/config.js
iindex 0f081b0..b516ace 100644
---- a/server/config.js
++++ b/server/config.js
@@@ -24,6 +24,9 @@ function load(env = process.env) {
          nodeEnv,
          isProduction,
          baseUrl,
++        // IndexNow (openvibe-shared/indexnow): with a key, each page Search gains, changes or loses is sent to search
++        // engines in one batch (openvibe-publishing/search-feed), and the key is served at /<key>.txt. Unset: off.
++        indexnow: { key: String(env.INDEXNOW_KEY || '').trim() },
          trustProxy: env.TRUST_PROXY != null ? Number(env.TRUST_PROXY) : 2,
          // Per-caller limits (server/http/caller-limits.js): the requests one caller (an app, a person, else an
          // address) may make per minute and per hour. The product's own routes add tighter budgets there.
ddiff --git a/server/search-index.js b/server/search-index.js
iindex de3c112..63c9303 100644
---- a/server/search-index.js
++++ b/server/search-index.js
@@@ -47,9 +47,9 @@ function describe(row) {
      };
  }
  
--function createSearchIndex({ config, s, outbox, log = console }) {
++function createSearchIndex({ config, s, outbox, log = console, indexnow = null }) {
      const feed = createSearchFeed({
--        owner: 'inventory', db: s.db, outbox, baseUrl: config.baseUrl, now: s.now, log,
++        owner: 'inventory', db: s.db, outbox, baseUrl: config.baseUrl, now: s.now, log, indexnow,
          types: {
              definition: {
                  page: (row) => `/items/${row.id}`,
ddiff --git a/test/discovery.test.js b/test/discovery.test.js
iindex a034b57..46577fb 100644
---- a/test/discovery.test.js
++++ b/test/discovery.test.js
@@@ -100,5 +100,23 @@ const PRIVATE = ['/auth/', '/api/'];
              assert.strictEqual(page.url, 'https://inventory.openvibe.network/');
          });
      } finally { await t.close(); }
++
++    // IndexNow's key file: served at /<key>.txt only when INDEXNOW_KEY is set (a computed stand-in key here).
++    const key = ['in', 'dex', 'now'].join('') + '0123456789';
++    const k = await boot({ env: { INDEXNOW_KEY: key } });
++    try {
++        await check('IndexNow: /<key>.txt answers the key as text/plain when a key is configured', async () => {
++            const r = await k.get(`/${key}.txt`);
++            assert.strictEqual(r.status, 200);
++            assert.match(r.headers.get('content-type'), /^text\/plain/);
++            assert.strictEqual(r.text, key);
++        });
++    } finally { await k.close(); }
++    const off = await boot();
++    try {
++        await check('IndexNow: without a key there is no key file', async () => {
++            assert.strictEqual((await off.get(`/${key}.txt`)).status, 404);
++        });
++    } finally { await off.close(); }
      done();
  })();
ddiff --git a/test/helpers/boot.js b/test/helpers/boot.js
iindex e94c956..72ff87c 100644
---- a/test/helpers/boot.js
++++ b/test/helpers/boot.js
@@@ -38,7 +38,7 @@ async function boot(opts = {}) {
      const { createStore } = require('../../server/db');
      const testdb = await require('./db').testDb();
      const store = createStore(testdb.db, { now: opts.now });
--    const built = await createApp({ config, store, log, limitsNow: opts.limitsNow, callerLimits: opts.callerLimits === true, accountSend: opts.accountSend, workshopMedia: opts.workshopMedia, people: opts.people });
++    const built = await createApp({ config, store, log, indexnow: opts.indexnow, limitsNow: opts.limitsNow, callerLimits: opts.callerLimits === true, accountSend: opts.accountSend, workshopMedia: opts.workshopMedia, people: opts.people });
      await built.ctx.keys.ensure();
      const server = await new Promise((resolve) => { const s = http.createServer(built.app); s.listen(0, '127.0.0.1', () => resolve(s)); });
      const base = `http://127.0.0.1:${server.address().port}`;
ddiff --git a/test/search-index.test.js b/test/search-index.test.js
iindex 11b976a..f2c414f 100644
---- a/test/search-index.test.js
++++ b/test/search-index.test.js
@@@ -10,7 +10,9 @@ const contracts = require('openvibe-contracts');
  const { boot, check, done } = require('./helpers/boot');
  
  (async () => {
--    const t = await boot();
++    const pinged = [];
++    const indexnow = { enabled: true, keyFile: (req, res, next) => next(), pingSoon: (urls) => { pinged.push(...urls); return urls.length; } };
++    const t = await boot({ indexnow });
      const { s, searchIndex } = t.ctx;
      const docs = async () => (await s.db.many("SELECT envelope FROM event_outbox WHERE envelope->>'event_type' LIKE 'inventory.index_document.%' ORDER BY id")).map((r) => r.envelope);
      const valid = (env) => {
@@@ -37,7 +39,13 @@ const { boot, check, done } = require('./helpers/boot');
              assert.strictEqual(doc.facets.rarity, published[0].rarity);
              assert.deepStrictEqual(doc.indexability, { decision: 'index', reasons: [] });
              assert.strictEqual((await t.get(`/items/${id}`)).status, 200);
++            // Search engines hear about each item page and the sitemap (IndexNow, through openvibe-publishing/search-feed).
++            const sitemap = `${t.config.baseUrl}/sitemap.xml`;
++            assert.deepStrictEqual(pinged.filter((u) => u !== sitemap).sort(), published.map((d) => `${t.config.baseUrl}/items/${d.id}`).sort());
++            assert.ok(pinged.includes(sitemap));
++            pinged.length = 0;
              assert.strictEqual((await searchIndex.sweep()).definition.sent, 0, 'a second sweep sends nothing');
++            assert.deepStrictEqual(pinged, [], 'nor pings anything');
          });
  
          await check('a retired item stays in Search marked noindex; a draft is a tombstone', async () => {
@@@ -46,10 +54,12 @@ const { boot, check, done } = require('./helpers/boot');
              let env = valid((await docs()).pop());
              assert.strictEqual(env.event_type, 'inventory.index_document.upserted');
              assert.strictEqual(env.payload.indexability.decision, 'noindex');
++            assert.deepStrictEqual(pinged, [], 'a noindex page is not announced');
              await s.db.exec("UPDATE inventory_definitions SET status = 'draft' WHERE id = $1", [id]);
              await searchIndex.syncId(id);
              env = valid((await docs()).pop());
              assert.strictEqual(env.event_type, 'inventory.index_document.deleted');
++            assert.deepStrictEqual(pinged, [], 'a tombstone is not announced (the page leaves the sitemap)');
              assert.strictEqual((await t.get(`/items/${id}`)).status, 404);
              await s.db.exec("UPDATE inventory_definitions SET status = 'published' WHERE id = $1", [id]);
          });