docs: rewrite ROADMAP_TO_V1 as production charter (2026-07-07)

Supersedes the stale 2026-01-29 Sonnet-era roadmap (targeted v0.10; about
half its milestones have since shipped). New charter: audit-verified
current state, seven workstream lanes with orchestration profiles, four
phases with fan-in reviews, and owner decisions D1-D5 as explicit phase
gates with provisional (vetoable) recommendations.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: hyperpolymath