…tion cascade ALGORITHM-LEVEL COMPLETE

After §47 recorded the cascade-started milestone (PRs #1450 + #1451 + #1452
scaffolding), the same-day continuation cycle closed §47.1 cascade roadmap
steps 4-6 at the algorithm level via PRs #1455, #1456, #1457.

## What landed (§47.1 cascade roadmap)

| Step | PR | Discharge |
|------|----|-----------|
| 4 | #1455 | FALSIFY-ATTN-SUB-002 PARTIAL_ALGORITHM_LEVEL — wires `QPostRope`+`KPostRope`+`AttnScores`+`AttnSoftmax` in `forward_traced_with_plan`; closes §47.4 parent-contract drift as side effect |
| 5 | #1456 | FALSIFY-ATTN-SUB-003 algorithm-level pinned via 2 drift-prevention tests; 0 LOC production change (loader is genuinely per-stage-agnostic, as spec predicted) |
| 6 | #1457 | FALSIFY-ATTN-SUB-004 BLOCKER_FIXTURE_ABSENT → PARTIAL_ALGORITHM_LEVEL on merge — extends `scripts/generate_qwen25_coder_fp16_stages.py` with `--with-attn-substages` (default ON) installing per-instance `Qwen2Attention.forward` monkeypatch under `attn_implementation="eager"` |

## Toyota Way correction during research (PR #1457)

The pre-impl research note estimated **7 missing stages, ~140 LOC**. Live source inspection during PR #1457 found **3 already captured** via existing forward hooks (`make_qkv_hook` derives qkv_matmul/qkv_bias from q_proj/k_proj/v_proj outputs via bias subtraction; `hook_o_proj_pre` captures `attention` as input to o_proj). Net: **4 stages, ~80 LOC monkeypatch**.

Per `feedback_no_guessing.md`. Cost-of-defect paid at the implementation layer (cheapest place once the research note had been authored from outdated docstring lines).

## Steps 7-8 require operator action

| Step | Blocker | Workaround |
|------|---------|-----------|
| 7 LIVE | (a) canonical `apr` binary built pre-#1451 — rejects `attn_scores` stage. (b) PyTorch/CUDA driver mismatch on host. | (a) `cargo build --release --features cuda --bin apr`. (b) operator updates driver OR `--device cpu` (multi-min). |
| 8 fix | Gated on step 7 bisection finding. | n/a — discovery-driven scope. |

## Net effects

- Spec v2.92.0 → **v2.93.0**.
- §47.1 cascade roadmap: **6/8 steps algorithm-level COMPLETE**; steps 7-8 LIVE/operator-gated.
- Coverage tally: 20+32 → **20+36** (+4 PARTIAL_ALGORITHM_LEVEL from `trace-attn-sub-stages-v1` v1.1.0 falsifiers landing on main when #1450 merged: SUB-001/002/003/005). SUB-004 stays BLOCKER until #1457 ships.
- **MODEL-1 ship %**: unchanged at **91%** (cascade is scaffold; ship % moves at SUB-004 LIVE DISCHARGE in step 7).
- **MODEL-2 ship %**: unchanged at **57%**.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>