Copy SoniCast?

Build me a Content Creation web app like SoniCast.

SoniCast does: Turn Any Content Into Professional Podcasts Transform documents, YouTube videos, or any topics into engaging podcasts with multiple voices, customizable styles, and professional audio quality in minut It reportedly makes about $95/mo, so the core idea clearly has demand — I want a lean version I can run and charge for.

Start from the open-source project ufal/whisper_streaming (https://github.com/ufal/whisper_streaming) — reuse what fits, strip its branding, and build the specifics below on top of it.

Requirements:
- Upload or record audio/video; transcribe with Whisper (local whisper.cpp or an API key from env).
- Speaker labels, timestamps, searchable transcript, and export (txt/srt/md).
- AI summary: key points, decisions, and action items with owners.
- Clean library view of past transcripts.

Also:
- Clean, modern, responsive UI with a thoughtful landing page.
- Email/password auth and a simple paid tier (Stripe test mode) so it's ready to charge.
- A README covering setup, environment variables, and how to deploy.

Ship a working MVP I can run locally first, then help me deploy it.