docs(roadmap): add phase orchestration system mirroring the reviewer audit workflow

Brings doc/roadmap/ to the same operational level as doc/reviewer/ by adding
the two missing structural files and updating existing docs to close the gap
identified in the system review.

New files:
- doc/roadmap/phase-orchestration.md  — master phase table (model assignments,
  session IDs, status, review-gate checklist); mirrors finding-orchestration.md
- doc/roadmap/session-prompts.md      — copy-paste-ready prompts for P1–P4
  (Haiku/Sonnet/Opus) + universal Opus review gate; mirrors reviewer/session-prompts.md

Updated files:
- CLAUDE.md: roadmap section now lists porting-status.md, phase-orchestration.md,
  session-prompts.md; reviewer section adds finding-orchestration.md and
  session-prompts.md; agentic-workflow section has direct "S3 is next / P1 is next"
  entry points so agents don't need to derive the next action from scratch
- doc/roadmap/phases.md: Current-focus table at the top (7 tracks, next session
  per track, gating); cross-links to geometry-central-comparison.md,
  software-landscape.md, complexity.md added in GC and 9b-analytic sections
- doc/roadmap/porting-status.md: snapshot date updated to 2026-05-31 (post S1+S2);
  test count replaced by reference to doc/api/tests.md; §4 gains four new solver
  rows (newton_core refactor, NewtonStatus enum, diagnostics, selectable clamp mode);
  §7 gains four new research-extension rows from S1/S2
- doc/roadmap/research-track.md: header companion-docs section links to
  novelty-statement.md, software-landscape.md, and phase-orchestration.md

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -375,9 +375,12 @@ Full line-by-line audit of all math-critical headers against `de.varylab.discret
 
 | Question | Document |
 |---|---|
-| Phases 1–10 with status and sub-tasks | `doc/roadmap/phases.md` |
+| Phases 1–13 with status, effort, and sub-tasks | `doc/roadmap/phases.md` |
+| Operational truth of which Java maths is in C++ today | `doc/roadmap/porting-status.md` |
 | Which Java classes are ported, which are planned, which are skipped? | `doc/roadmap/java-parity.md` |
 | New research items (beyond Java) — citations, acceptance criteria | `doc/roadmap/research-track.md` |
+| Phase orchestration — model assignments, priority, phase-session mapping | `doc/roadmap/phase-orchestration.md` |
+| Ready-to-paste session prompts for upcoming phases (P1–P4) | `doc/roadmap/session-prompts.md` |
 
 ### Tutorials & onboarding
 
@@ -397,6 +400,8 @@ Full line-by-line audit of all math-critical headers against `de.varylab.discret
 | Internal meeting agenda | `doc/reviewer/agenda.md` |
 | Reviewer landing index | `doc/reviewer/README.md` |
 | Hand-curated reviewer landing page (HTML, source-of-truth for codeberg pages) | `doc/reviewer/hub.html` |
+| Audit orchestration — model assignments, session sequence, status tracker | `doc/reviewer/finding-orchestration.md` |
+| Ready-to-paste session prompts for pending audit sessions (S3–S6) | `doc/reviewer/session-prompts.md` |
 
 The published hub lives at https://tmoussa.codeberg.page/ConformalLabpp/ (Doxygen index at `/doxygen.html`).  See the "Codeberg pages" quirk below for how it is republished.
 
@@ -419,6 +424,8 @@ Recommended loops when working in this repo. Prefer the cheapest gate that catch
 - **Before any commit**: run the four required gates locally — they mirror CI exactly and are seconds-cheap: `bash scripts/quality/license-headers.sh`, `python3 scripts/quality/cgal-conventions.py`, `bash scripts/quality/codespell.sh`, `bash scripts/quality/shellcheck.sh --strict`.
 - **Before tagging a release**: also run the two now-un-gated structural gates (test-cgal is disabled in CI): `BUILD_DIR=build bash scripts/check-test-counts.sh` and `bash scripts/try_it.sh`.  Update `CHANGELOG.md`, `CITATION.cff`, and the `doc/api/tests.md` counts (single source of truth).
 - **Touching public-API headers**: rebuild Doxygen (`cmake --build build --target doc`) and re-check coverage (`bash scripts/doxygen-coverage.sh --threshold 100`); regenerate `doc/api/headers.md` via `python3 scripts/gen-headers-md.py` (or `bash scripts/regen-docs.sh`).
+- **Starting work on an audit finding**: open `doc/reviewer/finding-orchestration.md`, pick the next ⬜ pending session, copy its prompt from `doc/reviewer/session-prompts.md`, set the named model, and go. **S3 is next** (H3/H4/H5/V5/V6, Sonnet → Opus review).
+- **Starting work on a roadmap phase**: open `doc/roadmap/phase-orchestration.md`, pick the next ⬜ pending phase-session, copy its prompt from `doc/roadmap/session-prompts.md`, set the named model, and go. **P1 is next** (9g.1 + 9h.1 + 9h.2 + 9d.3, Haiku → Opus review).
 - **Landing to `main`** (origin is protected): branch → push to `origin` → open PR via `gh`/Gitea API → merge via API → also push `codeberg/main` directly → keep both remotes in sync.
 - **Republishing the reviewer hub**: see the Codeberg `pages` quirk below — manual force-push of an orphan branch; verify the live URL with a cache-bust query.
 - **Delegation**: this repo's heavy builds are slow on the ARM64 runner — when a task is genuinely parallelisable and independent, consider a background agent; otherwise handle inline.  Always verify an agent's actual diff, not just its summary.