Explore optional browser-extension companion for downloads

[Sportinger]

This discussion continues the architecture question from the closed issue:

• Closed issue: https://github.com/Sportinger/MasterSelects/issues/78
• Topic: whether MasterSelects should explore an optional browser-extension companion for online-video downloads.

Context

Issue #78 originally asked whether yt-dlp could be embedded directly into the normal MasterSelects browser app, possibly through WASM/RustPython/Pyodide-style approaches.

After checking the references, the current conclusion is still:

• Running Python or WASM in the browser is possible.
• That does not bypass the browser security model.
• A normal web app is still constrained by CORS, Same-Origin, forbidden request headers, cookie isolation, no direct TCP/UDP sockets, and no native subprocesses.
• The existing Native Helper remains the right architecture for local/private downloads because it can run yt-dlp, access local files, retry with browser cookies where appropriate, and stream progress back to MasterSelects.

Why this is still worth discussing

The dlPro reference is interesting because it shows a different architecture: a browser extension with extra permissions, not a normal website. That makes a separate companion-extension idea more plausible than direct browser embedding.

Possible direction:

• Keep the normal MasterSelects web app unchanged for this path.
• Keep the Native Helper as the primary local download route.
• Explore whether an optional MasterSelects browser extension could assist with download metadata, page context, cookies, or extension-permission-only workflows.
• Avoid treating this as a replacement for the Native Helper until the security, UX, store-policy, and maintenance costs are understood.

Open questions

• Would a companion extension add enough value beyond the Native Helper?
• Which tasks would actually need extension privileges?
• Would Chrome/Firefox/Edge store policies allow the relevant functionality?
• How should trust, permissions, user consent, and project import handoff work?
• Is this worth maintaining alongside the Native Helper?

Recommendation from the closed issue: do not implement yt-dlp as direct browser embedding, but use this discussion for the optional browser-extension-companion route.