docs(delphi): overnight pre-cutover audit (s6) — CUTOVER_RUNBOOK + journal

[jucor]

Audit of the 32-PR stack for the clojure-off/python-on decision:
CI fixes (cwd assertion), Copilot coverage completed (18 requested),
two stale threads resolved via stack citations, #2658 sharding reviewed
(ship), CUTOVER_RUNBOOK.md with evidence base + risk register + 3-step
same-day cutover plan.

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

commit-id:7f7b9373

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Stack:

• refactor(math): PR 14b/14c — readable two-phase stats + blob-injection pins #2673
• docs(delphi): s7 goal state + journal — mode collapse executed, battery 20/20 #2672
• feat(delphi): mode collapse C7 — harness identifier purge + flag machinery deletion #2671
• feat(math): mode collapse C5+C6 — driver mod semantics + poller flag plumbing deleted #2670
• feat(math): mode collapse C4 — delete-only improved branches (ban filter, tally sources, blob shape) #2669
• feat(math): mode collapse C3 — powerit warm-start PCA + legacy kmeans as the only solvers (item 8 parked) #2668
• feat(math): mode collapse — Q2 prev-tick group-votes unconditional (item 5 parked) #2667
• feat(math): mode collapse — Q15 watermark drop unconditional (item 4 parked) #2666
• feat(math): mode collapse — degenerate guards become the only path (item 2 parked) #2665
• feat(delphi): certify battery speedup — engine-scoped py cache + parallel entries (Phase 0) #2664
• fix(delphi): Copilot-review triage batch — 16 findings across the stack #2663
• docs(delphi): overnight pre-cutover audit (s6) — CUTOVER_RUNBOOK + journal #2659 ⬅
• feat(delphi): zid-sharding for the math poller — one shard = one process #2658
• ci: run postgres integration tests #2637
• feat(delphi): poller-equivalence harness (goal condition 2) — PASSES live on vw + pc-meta-02 #2657
• feat(math): moderation + restart replay parity — mod_update, restart-seam restore, Q13-Q18 #2656
• docs(delphi): R1-parity goal docs, journal (2026-07-18 → 07-24 s5), quirks + divergence ledger #2626
• feat(delphi): Q12 carve-out — pin the cold-tick PCA start to ones in both replay drivers #2655
• feat(math): Q11 — replicate vectorz distance cancellation in legacy kmeans #2654
• feat(math): small-N degenerate parity — run the real math on tiny matrices in clojure-legacy mode #2653
• feat(delphi): Q10 carve-out — pin large-conv cutoffs to certify the deterministic full-PCA path #2652
• feat(delphi): replay loader resolves private datasets under real_data/.local #2651
• feat(math): Clojure hash-map iteration order for the in-conv greedy tie-break (legacy) #2650
• feat(math): clojure-legacy blob emission + selection parity — Clojure-exact math_main at step 0 #2649
• feat(delphi): acceptance canonicalization — suppress cross-engine ordering artifacts in certify comparer #2648
• feat(delphi): certify.py battery runner + focuser + fingerprint ledger (Spec A, Phase 0) #2647
• feat(delphi): prodclone extractor — feature-filtered dataset export (Spec B) #2646
• feat(math): un-mirror priority_metric (#2571 resolved) + Q2 prev-tick group-votes #2645
• feat(math): participant-ban leak replication in clojure-legacy mode (Q1) #2644
• feat(delphi): Clojure timing probe (Spec C) #2643
• feat(math): degenerate-tick group-clusterings overwrite + <2-participants edge (legacy mode) #2642
• refactor(math): move impl-flag resolver to polismath/utils/env_flags.py #2641
• feat(delphi): Python math poller service (phase 1) — Clojure math-container replacement #2625
• fix(delphi): Clojure-parity math writers + committing write path in PostgresClient #2624
• feat(math): in-conv greedy floor + persistent carry (PR-E) #2623
• feat(math): Clojure-exact base-cluster lineage + warm start (PR-C) #2622
• feat(math): replay harness H-B — Clojure Mode A driver (dev/replay.clj) + cross-language comparer shim #2621
• feat(math): group-k-smoother in clojure-legacy engine mode (PR-D smoother) #2620
• feat(math): PCA warm start in clojure-legacy engine mode (PR-B) #2640
• feat(math): add POLISMATH_ENGINE_MODE flag + prev-tick warm-start scaffolding (PR-A) #2618
• feat(delphi): replay harness H-A — schedule spec+slicer, Python driver, store, step comparer, CLI #2639
• fix(delphi): cold-start generator copies FULL revote history (no DISTINCT ON dedup) #2638
• fix(math): correct comment-extremity sign in pca_project_cmnts (D1b) #2615
• docs(delphi): add math-algorithm history & routing-regression reference #2613

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⚠️ Part of a stack created by spr. Do not merge manually using the UI - doing so may have unexpected results.