Stage B 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.

ddiff --git a/server/observability.js b/server/observability.js
iindex 33a8659..409c7a4 100644
---- a/server/observability.js
++++ b/server/observability.js
@@@ -20,10 +20,13 @@ function createHostReadiness({ store, blobs, auth, outbox, release = null, minFr
          checks: [
              {
                  name: 'db', required: true,
++                // A real round trip that names the store (postgresql / pglite), and the charter tables present.
                  check: async () => {
++                    const r = await db.ready();
++                    if (!r.ok) return r.error;
                      const names = new Set((await db.prepare("SELECT table_name AS name FROM information_schema.tables WHERE table_schema = current_schema()").all()).map((r) => r.name));
                      const missing = CHARTER_TABLES.filter((t) => !names.has(t));
--                    return missing.length ? `missing ${missing.join(', ')}` : true;
++                    return missing.length ? `missing ${missing.join(', ')} (migrations did not run)` : { ok: true, detail: r.detail };
                  },
              },
              { name: 'storage', required: true, check: () => blobs.writable() },