Proposal: optional .bit (Namecoin) onboarding step

[mstrofnone]

Filed as a PR rather than an issue because issues are disabled on this repo. Treat this thread as the discussion; the file itself can be deleted before merging or kept as design notes.

This PR adds a single PROPOSAL-bit-onboarding.md proposing an optional, skippable step in the nstart wizard for users who want to claim a sovereign Nostr address (.bit via Namecoin). No wizard logic is touched in this PR — it's purely a design proposal so the maintainers can bless or veto the shape before code is written.

The full doc is in the diff; the short version:

• nstart deliberately omits a NIP-05 step today because the DNS path's onboarding cost is too high.
• NIP-05-over-Namecoin removes the DNS/TLS/HTTP requirement: identity lives on-chain.
• The library tier (nostr-tools, rust-nostr, dart-nostr) and the client tier (Amethyst merged; Nostur, nostrmo, jumble, futr, 0xchat, Aegis, lumilumi, ants, alphaama, nosotros, nostter all open) have landed or are about to land .bit resolution support.
• nstart is the right place for the "claim a sovereign address" front-of-funnel decision.

NIP draft: nostr-protocol/nips#2349.

Library PRs: nbd-wtf/nostr-tools#533, rust-nostr/nostr#1367.

Open questions for the maintainers (full text in the doc):

1. Provisioning partner — willing to integrate with a registrar, or self-host-only?
2. Where in the wizard — between bunker and finish?
3. Default state — skipped by default, prominent skip?
4. Calling-app integration — add an anip= query param?

Once the shape is blessed, the first code PR would be UI scaffolding only (a new optional route + store flag), with the provisioning back-end as a follow-up.

Happy to delete this file and convert the discussion into a different format if there's a venue you prefer.