Readiness names the store: the db check makes a real round trip (db.ready) and reports postgresql or pglite with the pool, as the other services on PostgreSQL do. npm test 23/23.

ddiff --git a/server/observability.js b/server/observability.js
iindex 501224f..d11535e 100644
---- a/server/observability.js
++++ b/server/observability.js
@@@ -32,7 +32,15 @@ function createAiReadiness({ db, registry, pool, keys, runs, release = null }) {
          service: 'ai',
          release,
          checks: [
--            { name: 'db', required: true, check: async () => ((await db.prepare('SELECT COUNT(*) AS n FROM providers').get()).n > 0 ? true : 'the provider registry is empty') },
++            {
++                name: 'db', required: true,
++                // A real round trip that names the store (postgresql / pglite), and the provider registry present.
++                check: async () => {
++                    const r = await db.ready();
++                    if (!r.ok) return r.error;
++                    return (await db.prepare('SELECT COUNT(*) AS n FROM providers').get()).n > 0 ? { ok: true, detail: r.detail } : 'the provider registry is empty';
++                },
++            },
              {
                  name: 'workflows', required: true,
                  check: async () => {