Kann ich Jasper vibecoden?

Build me a personal marketing-copy generator to replace Jasper. Requirements:

- A local web app: Node + Express + better-sqlite3 on localhost:4850, plain
  server-rendered forms, no frontend framework.
- A brand/ folder of Markdown files: voice.md (tone rules, banned words),
  audience.md, product.md. Every generation prepends these to the prompt
  automatically.
- Template library in SQLite: blog outline, landing-page hero, product description,
  cold email, tweet thread. Each template is a prompt with {{variables}} filled in
  from a small form.
- Calls the Anthropic or OpenAI API (key and model name in .env), streams into the
  page, and always produces 3 variants side by side.
- Every output saved with template, inputs, chosen variant, and a campaign label;
  past outputs browsable and searchable by campaign.
- A rewrite box: paste any draft, get it back in my brand voice.
- Everything stays on my machine except the LLM calls. No accounts, no telemetry.
- Out of scope: team collaboration, approval workflows, and multi-writer brand
  governance. This is a one-person tool.
- README: .env keys and how to tune the brand files, that is where the quality lives.

Antworte mir auf Deutsch. Oberfläche, Kommentare und README auf Deutsch, alle Bezeichner wie Tabellen, Spalten, Variablen, Routen und Dateinamen bleiben Englisch.