Adds docs/nip71-onboarding-plan.md and pre-launch TODO 17c for the agreed
two-way NIP-71 interop:
- Phase 1 (first): cross-ecosystem dedup — prefer the bitvid (30078) version,
show exactly one in every grid; identity = author + import-link/hash/infohash.
- Phase 2: creator-initiated self-import (model A) — re-host to the creator's
storage (CDN) + WebTorrent, publish a signed 30078 with an imported-from
provenance tag. No forging others' notes; no instance auto-rehost.
Planning only; no code changes.
Co-Authored-By: Claude Opus 4.8 <[email protected]>