- add a PR-audit research log entry covering the clean takeaways from pull requests openai#36 through openai#70
- promote long-context training plus matching long-context eval as a first-class clean branch based on PR openai#61 and PR openai#63
- refine mixed-precision export notes to emphasize using int6/int8 byte savings to fund wider MLP capacity, based on PR openai#65
- update the current snapshot and research thesis so future agents do not over-focus on exporter-only ideas after the broader PR sweep

- fix the PR-audit notes to attribute the long-context branch to PR openai#65 rather than PR openai#61
- record PR openai#61 as schedule-side evidence about long warmdown reducing quantization damage
- keep the ideas backlog aligned with the actual GitHub PR content before using it for next-step decisions

* Warmdown-quantization co-optimization, val_bpb=1.2154

Novel finding: aggressive LR decay (WARMDOWN_ITERS=20000) reduces int8 quantization
penalty from 0.014 to 0.005 BPB. Combined with FP16 tied embeddings and moderate
NTK-RoPE extrapolation (eval@1408).

Full warmdown sweep across 10 values and detailed analysis in README.

* breakthrough: 1.1574 BPB via int6 + MLP 3x + sliding window stride=256

---------

Co-authored-by: Sam Larson <saml212@users.noreply.github.com>

* Warmdown-quantization co-optimization, val_bpb=1.2154

Novel finding: aggressive LR decay (WARMDOWN_ITERS=20000) reduces int8 quantization
penalty from 0.014 to 0.005 BPB. Combined with FP16 tied embeddings and moderate
NTK-RoPE extrapolation (eval@1408).

Full warmdown sweep across 10 values and detailed analysis in README.

* breakthrough: 1.1574 BPB via int6 + MLP 3x + sliding window stride=256

---------

Co-authored-by: Sam Larson <saml212@users.noreply.github.com>

* Warmdown-quantization co-optimization, val_bpb=1.2154

Novel finding: aggressive LR decay (WARMDOWN_ITERS=20000) reduces int8 quantization
penalty from 0.014 to 0.005 BPB. Combined with FP16 tied embeddings and moderate
NTK-RoPE extrapolation (eval@1408).

Full warmdown sweep across 10 values and detailed analysis in README.

* breakthrough: 1.1574 BPB via int6 + MLP 3x + sliding window stride=256

---------

Co-authored-by: Sam Larson <saml212@users.noreply.github.com>

After PR openai#61 (byte-disjoint corpus split + assert_train_val_disjoint guard)
shipped, fix-verify-s43 ran end-to-end on the post-fix pipeline and produced
BPB 1.5492 at step=12000 — well below Gate-2 threshold 1.85 (margin +0.30).

## What this commit changes

- README.md  : leads with the honest Gate-2 pass; revised 5-way taxonomy
- LEAK_INVESTIGATION.md : retraction header explaining the 216-row overcount
- trios-igla-1/README.md + config.yaml : updated to point at fix-verify-s43
- ledger_2026-04-30.sql.gz : refreshed snapshot with new last_error markers

## 5-way reclassification (Neon last_error column)

|                                      | count |
|---|--:|
| post-openai#61 honest Gate-2 pass          |   1 |
| post-openai#61 early-stopped < step 9000   |   4 |
| pre-openai#61 W-6 numerical collapse       |  46 |
| **pre-openai#61 leak (real)**              |  42 |
| **warmup artifact (NOT a leak)**     | 179 |

The 179 'warmup artifact' rows are early-stopped runs whose printed
val_bpb stayed at 0.0000 for steps 1-8000 due to a trainer-side eval-loop
bug (filed as trios-trainer-igla#62). On the post-openai#61 image, fix-verify-s43
escaped warmup at step=9000 and converged to 1.5492 by step=12000 —
proving the artifact is trainer-side, not data-side.

## Pipeline as flown for fix-verify-s43

  trios-trainer-igla : commit 9517980d (post-openai#61 byte-disjoint corpus)
  trios-railway      : commit 69c3467 (no --ctx flag)
  + openai#56 --ctx accept on trainer
  + openai#58 smoke_train + stdout.flush()
  + openai#59 panic hook + startup diagnostic

## Refs

  trios-trainer-igla#56,openai#58,openai#59,openai#60,openai#61,openai#62 (all merged or filed)
  trios-railway@69c3467
  trios-railway#100,openai#101,openai#105 (Scarabaeus Engine track)

R5-honest. We retract the 216-row mass leak flag and submit fix-verify-s43
as our first honest Gate-2 pass candidate.

Anchor: phi^2 + phi^-2 = 3.