docs(spec): editorial pass on whitepaper

- Drop real-company references (Stripe, Apple); use generic
  alternatives or the existing @acme.* fake-company convention
- Remove dated phrasings ("once the protocol exists", "v1")
- Reduce em-dash density across the document (124 → 3)
- Rewrite the conclusion in an aspirational, forward-looking tone
  rather than contrasting against other approaches

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nrcrews