feat(learner): package scaffold, auth tables migration, migrations runner

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/feature-learner/test/helpers.ts

@@ -0,0 +1,35 @@
+import { test } from "bun:test";
+import { connect, migrate, type Db } from "@stc/db";
+import { runMigrations } from "../src/server/migrate";
+
+const PG = process.env.STC_TEST_PG_URL;
+
+/** Fresh migrated in-memory SQLite (and a fresh Postgres schema when STC_TEST_PG_URL is set), with learner migrations applied. */
+export function forEachDb(name: string, fn: (db: Db) => Promise<void>, timeout?: number): void {
+  test(`${name} [sqlite]`, async () => {
+    const db = await connect("sqlite://:memory:");
+    try { await migrate(db); await runMigrations(db); await fn(db); } finally { await db.close(); }
+  }, timeout);
+  if (!PG) return;
+  test(`${name} [postgres]`, async () => {
+    const { db, drop } = await pgSchemaDb();
+    try { await migrate(db); await runMigrations(db); await fn(db); } finally { await drop(); }
+  }, timeout);
+}
+
+export async function pgSchemaDb(): Promise<{ db: Db; drop(): Promise<void> }> {
+  const schema = `t_${Bun.randomUUIDv7().replaceAll("-", "")}`;
+  const admin = await connect(PG!);
+  await admin.sql.unsafe(`CREATE SCHEMA ${schema}`);
+  const u = new URL(PG!);
+  u.searchParams.set("options", `-c search_path=${schema}`);
+  const db = await connect(u.toString());
+  return {
+    db,
+    async drop() {
+      await db.close();
+      await admin.sql.unsafe(`DROP SCHEMA ${schema} CASCADE`);
+      await admin.close();
+    },
+  };
+}