adding new unique index, adding button to start now

lib/services/storage/migrations/sql/2.new-indexes-for-listings.js

@@ -0,0 +1,10 @@
+// Migration: there needs to be a unique index on job_id and hash as only
+// this makes the listing indeed unique
+
+export function up(db) {
+  db.exec(`
+    DROP INDEX IF EXISTS idx_listings_hash;
+    CREATE UNIQUE INDEX IF NOT EXISTS idx_listings_job_hash
+      ON listings (job_id, hash);
+  `);
+}