docs(reviewer): update audit status + add finding-orchestration plan

Session 1 (2026-05-31) resolved 26 findings across Sonnet/Haiku/Opus; 298/298
CGAL tests green.  Bring the audit docs in line with reality:

- README.md: G0 banner now records that the original authors were contacted by
  email about porting/relicensing rights (awaiting reply); headline-status cells
  updated per finding; new "Session 1 — implemented" record; link to the plan.
- Per-audit resolution banners (api-performance, numerical-stability,
  input-validation, test-coverage, math-citation, thread-safety) + G0-blocked
  banners (cgal-submission, dependency-license).
- NEW finding-orchestration.md: the meta-plan mapping every finding to a session,
  an implementing model (Haiku/Sonnet/Opus by the "how much must be understood"
  rule), and an Opus review gate after each implementation session.  Records S1
  (done) and lays out S2–S6 so the next session can be picked up cold.

Docs only — no code change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

doc/reviewer/cgal-submission-readiness-audit-2026-05-31.md

@@ -12,6 +12,13 @@ act on it without prior context.
 
 Status legend: ⛔ Blocker (submission rejected on sight) · 🔴 Critical · 🟡 Important · 🔵 Polish
 
+> **🔄 Status (2026-05-31):** the whole package — **G0** (porting rights), and
+> everything it gates (**G1–G12**) — is **blocked pending the original authors'
+> reply**. The authors have been **contacted by email** asking to clarify
+> porting/relicensing rights. No layout/license/header work proceeds until a
+> written answer exists. Scheduled as **S6** (Opus, after G0/G1) in
+> [`finding-orchestration.md`](finding-orchestration.md).
+
 > **Companion documents:**
 > - `external-audit-2026-05-30.md` — port-faithfulness bugs
 > - `test-coverage-error-handling-audit-2026-05-31.md` — test gaps + error handling