src/project-store.js

const DB_NAME = "ai-banner-lab";
const STORE = "projects";

function database() {
  return new Promise((resolve, reject) => {
    const request = indexedDB.open(DB_NAME, 1);
    request.onupgradeneeded = () => request.result.createObjectStore(STORE, { keyPath: "id" });
    request.onsuccess = () => resolve(request.result);
    request.onerror = () => reject(request.error);
  });
}

export async function saveProject(project) {
  const db = await database();
  await new Promise((resolve, reject) => {
    const transaction = db.transaction(STORE, "readwrite");
    transaction.objectStore(STORE).put(project);
    transaction.oncomplete = resolve;
    transaction.onerror = () => reject(transaction.error);
  });
  db.close();
}

export async function listProjects() {
  const db = await database();
  const projects = await new Promise((resolve, reject) => {
    const request = db.transaction(STORE, "readonly").objectStore(STORE).getAll();
    request.onsuccess = () => resolve(request.result.sort((a, b) => b.updatedAt - a.updatedAt).slice(0, 20));
    request.onerror = () => reject(request.error);
  });
  db.close();
  return projects;
}