Lohnt sich dein eigenes HEY?

Build me an email client with HEY's screening and bundling ideas, running on
top of a mailbox I already pay for (Fastmail, Gmail, anything with IMAP).
Requirements:

- A local web app: Node + Express + better-sqlite3, binds to localhost;
  imapflow for reading, nodemailer for sending, creds in .env.
- The screener: mail from first-time senders lands in a screening view where I
  approve or block; decisions persist in SQLite and apply to all future mail.
- Bundles: approved senders get a category; newsletters render in a batched
  feed view, receipts in a paper-trail list; only approved humans hit the
  inbox.
- Reply-later: mark a thread and it sits in a persistent to-answer stack until
  cleared.
- Write decisions back as IMAP folders and labels so my phone's mail app
  roughly mirrors the sorting.
- Strip remote images in the reading pane by default.
- No accounts of its own, no telemetry; mail stays at my provider.
- Out of scope: running an SMTP server, custom domains, and mobile apps. Do not
  replace the mail service itself; deliverability and spam reputation are the
  product and cannot be rebuilt solo.
- README: per-provider app-password setup, and a warning that Gmail OAuth is a
  project of its own, use an app password or Fastmail to keep this a weekend.