fix(delphi): Clojure-parity math writers + committing write path in PostgresClient

[jucor]

The four math writers had zero live callers (verified: only commented-out refs
in test_postgres_real_data.py) and did not match the Clojure SQL. Rewrite them
to the verified Clojure statements:

• write_math_main: caching_tick = COALESCE((select max(caching_tick)+1 from
  math_main where math_env=?), 1) upsert (postgres.clj:323-338). The prod TS
  prefetch (pca.ts:84-151) polls caching_tick > last, so this is fidelity-critical.
• increment_math_tick: atomic INSERT ... ON CONFLICT ... math_tick+1 RETURNING
  (postgres.clj:292-295), replacing the read-modify-write.
• add MathBidToPid model + write_math_bidtopid (net-new; participants.ts depends
  on it).
• write_participant_stats: add the shared math_tick (Clojure writes all three
  data tables with one tick, conv_man.clj:158-169).

Add a committing write path _write_returning (engine.begin()) and route the four
writers through it: query() uses engine.connect() (SQLAlchemy 2.0
commit-as-you-go) which rolls back INSERTs on close. Mocked unit tests could not
catch this; the postgres integration test did. execute() now commits too.

Add global watermark reads for the poll loops: poll_votes_since (WHERE
created > wm ORDER BY zid,tid,pid,created, sign-flipped, postgres.clj:132-145)
and poll_moderation_since (postgres.clj:148-161). Add ORDER BY zid,tid,pid,created
to poll_votes so the full-history rebuild reproduces Clojure's row-insertion
order (base-cluster IDs seed k-means -> parity).

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

commit-id:6324b652

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Stack:

• 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.

[Copilot]

Pull request overview

This PR updates Delphi’s Postgres integration to better match the production Clojure SQL semantics and to ensure math writes actually commit under SQLAlchemy 2.x, while also hardening JSON serialization of math blobs that may contain NumPy scalar types.

Changes:

• Add a committed write helper (_write_returning via engine.begin()) and route math upsert writers through it; execute() now commits as well.
• Rewrite/extend math table writers for Clojure parity (including atomic increment_math_tick and a new math_bidtopid model/writer).
• Add global poll helpers (poll_votes_since, poll_moderation_since) and enforce deterministic row ordering for vote polling; add shared NumPy-to-JSON serialization helper + regression test coverage.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
delphi/polismath/database/postgres.py	Adds committed write path, Clojure-parity upsert SQL for math writers, atomic tick increment, deterministic vote ordering, and global watermark poll helpers.
delphi/polismath/utils/serialization.py	Introduces shared convert_numpy_types helper for JSON serialization of NumPy scalars/arrays.
delphi/polismath/regression/utils.py	Hoists and re-exports convert_numpy_types from the new shared serialization module for backward compatibility.
delphi/tests/test_math_writer_numpy_serialization.py	Adds regression tests ensuring math writers can serialize real computed blobs containing NumPy integer scalars.

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