Tips: request telemetry in its own table, 30-day retention (#58)

ddiff --git a/migrations/0004_telemetry.sql b/migrations/0004_telemetry.sql
nnew file mode 100644
iindex 0000000..14260fa
---- /dev/null
++++ b/migrations/0004_telemetry.sql
@@@ -0,0 +1,28 @@
++-- phase: expand
++-- Request telemetry (openvibe-sdk/telemetry telemetrySchema()): one row per aggregated sample, pruned after 30 days (server/index.js).
++CREATE TABLE IF NOT EXISTS telemetry_samples (
++    id                    bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
++    at                    timestamptz NOT NULL,
++    service               text NOT NULL,
++    project               text,
++    subject               text,
++    resource              text,
++    provider              text,
++    node                  text,
++    cell                  text,
++    region                text,
++    operation             text NOT NULL,
++    latency_ms            double precision,
++    queue_delay_ms        double precision,
++    ttfb_ms               double precision,
++    throughput_per_second double precision,
++    bytes                 bigint,
++    status                text,
++    cache_status          text,
++    cost_estimate         double precision,
++    route_epoch           bigint,
++    trace_id              text,
++    extra                 jsonb NOT NULL DEFAULT '{}'::jsonb
++);
++CREATE INDEX IF NOT EXISTS telemetry_samples_at_idx ON telemetry_samples (at);
++CREATE INDEX IF NOT EXISTS telemetry_samples_service_idx ON telemetry_samples (service, operation, at);
ddiff --git a/server/app.js b/server/app.js
iindex 4096586..78a86aa 100644
---- a/server/app.js
++++ b/server/app.js
@@@ -80,6 +80,9 @@ function createApp(opts = {}) {
      const metrics = require('openvibe-shared/metrics').instrument(app, {
          service: 'tips', release: release.release, registry, skip: (req) => /^\/overlay\/[^/]+\/events$/.test(req.path),
      });
++    // Request telemetry (openvibe-sdk/service): a no-op until server/index.js calls telemetry.init(); an overlay's event
++    // stream lasts as long as the overlay is open, so it is not a request latency (as for the metrics above).
++    { const { telemetry } = require('openvibe-sdk/service'); app.use((req, res, next) => (/^\/overlay\/[^/]+\/events$/.test(req.path) ? next() : telemetry.middleware(req, res, next))); }
      app.use(http.middleware());
      app.use((req, res, next) => {
          res.setHeader('X-Content-Type-Options', 'nosniff');
ddiff --git a/server/index.js b/server/index.js
iindex bb0b8bb..8bc5dc5 100644
---- a/server/index.js
++++ b/server/index.js
@@@ -21,7 +21,8 @@ const { openDb, migrate } = require('./db');
  const { createApp } = require('./app');
  const { createValkey } = require('openvibe-sdk/valkey');
  const { createRegistry } = require('openvibe-shared/metrics');
--const { gracefulStop } = require('openvibe-sdk/service');
++const { gracefulStop, telemetry } = require('openvibe-sdk/service');
++const { createPgTelemetrySink, startTelemetryRetention } = require('openvibe-sdk/telemetry');
  const { startSubscriptions } = require('openvibe-sdk/account-data');
  
  /**
@@@ -41,7 +42,7 @@ function createLifecycle({ server, app, timers = [], exit, signals, extra = [] }
              () => outbox.stop(),
              ...extra,
          ],
--        close: [() => db.close(), () => { if (valkey) return valkey.close(); }],
++        close: [async () => { if (app.locals.telemetryRetention) await app.locals.telemetryRetention.stop(); await telemetry.stop(); }, () => db.close(), () => { if (valkey) return valkey.close(); }],
      });
  }
  
@@@ -73,6 +74,10 @@ async function start() {
          console.log(`[Tips] billing ${config.billing.url}; chat adapter ${config.chat.adapter}; events relay ${outbox.enabled ? `→ ${config.events.url}` : 'off (outbox accumulates)'}; billing events ${config.events.webhookSecrets.length ? 'accepted' : 'not accepted (TIPS_EVENTS_SECRET unset)'}`);
      });
      server.keepAliveTimeout = 65_000;
++    // Request telemetry (openvibe-sdk/service, plan T1): one aggregated sample per route template, method and status
++    // class each minute, stored in telemetry_samples; rows older than 14 days go daily.
++    telemetry.init({ service: 'tips', sink: createPgTelemetrySink({ db: db, log: console }), skipPrefixes: ['/shared'], intervalMs: 60_000 });
++    app.locals.telemetryRetention = startTelemetryRetention({ db: db, log: console, olderThanDays: 14 });
  
      // The two account subscriptions at OpenVibe.Events (ADR-033), created when missing; off without EVENTS_URL,
      // TIPS_EVENTS_SECRET or the client secret. The billing.* ones stay scripts/subscribe.js's.
ddiff --git a/test/telemetry.test.js b/test/telemetry.test.js
nnew file mode 100644
iindex 0000000..d71103b
---- /dev/null
++++ b/test/telemetry.test.js
@@@ -0,0 +1,50 @@
++'use strict';
++/**
++ * Request telemetry (openvibe-sdk/service, plan T1 step 10): app.js mounts the process-wide telemetryMiddleware (a no-op
++ * until init), server/index.js calls telemetry.init() for service 'tips' with a PostgreSQL sink, starts the 14-day
++ * retention and flushes on stop. Five hits on one route flush as ONE aggregated http.request sample; /metrics and
++ * /shared make none; the retention deletes only rows older than 14 days.
++ */
++const assert = require('assert');
++const fs = require('fs');
++const path = require('path');
++const { telemetry } = require('openvibe-sdk/service');
++const { pruneTelemetry } = require('openvibe-sdk/telemetry');
++const { boot } = require('./helpers/app');
++(async () => {
++    const read = (p) => fs.readFileSync(path.join(__dirname, '..', p), 'utf8');
++    assert.match(read('server/index.js'), /telemetry\.init\(\{ service: 'tips', sink: createPgTelemetrySink\(/, 'index.js starts the collector');
++    assert.match(read('server/index.js'), /startTelemetryRetention\(/, 'index.js starts the retention');
++    assert.match(read('server/index.js'), /[Rr]etention\.stop\(\); await telemetry\.stop\(\);/, 'the stop flushes');
++
++    const t = await boot();
++    const samples = [];
++    telemetry.init({ service: 'tips', sink: async (batch) => { samples.push(...batch); }, intervalMs: 3600e3 });
++    const requests = () => samples.filter((s) => s.operation === 'http.request');
++    try {
++        for (let i = 0; i < 5; i++) assert.strictEqual((await t.call('GET', '/', { token: null })).status, 200);
++        await telemetry.flush();
++        const hit = requests().filter((s) => s.resource === '/' && s.status === '2xx');
++        assert.strictEqual(hit.length, 1, JSON.stringify(requests()));
++        assert.strictEqual(hit[0].service, 'tips');
++        assert.strictEqual(hit[0].extra.count, 5);
++
++        samples.length = 0;
++        await await t.call('GET', '/metrics', { token: null });
++        await await t.call('GET', '/shared/navbar.js', { token: null });
++        await telemetry.flush();
++        assert.deepStrictEqual(requests(), [], '/metrics and /shared make no sample');
++
++        const db = t.domain.db;
++        await db.query('DELETE FROM telemetry_samples');
++        const insert = (days) => db.query("INSERT INTO telemetry_samples (at, service, operation) VALUES (now() - make_interval(days => $1), 'tips', 'http.request')", [days]);
++        await insert(20);
++        await insert(1);
++        assert.strictEqual(await pruneTelemetry({ db, olderThanDays: 14 }), 1);
++        assert.strictEqual((await db.query('SELECT count(*)::int AS n FROM telemetry_samples')).rows[0].n, 1);
++        console.log('telemetry ok');
++    } finally {
++        await telemetry.stop();
++        await t.close();
++    }
++})().catch((err) => { console.error(err); process.exit(1); });