feat(sap): prove CATS field ABI binding, Quack folds and edge adapters

.claude/board/AGENT_LOG.md

@@ -1,3 +1,22 @@
+## 2026-09-22 — SAP/CATS fold-first dependency stack (PR #1257, unmerged)
+
+- Substrate: ndarray #318 `d0376505`; lance-graph #1256 `4d27032e`.
+  #1246 and #1247 are already ancestors. SAP CI pins the ndarray commit.
+- `CatsQuery` lowers one `Agg::GroupSumI32` through Quack. Bounded tile
+  scratch remains; no population bitmap is retained by binding or aggregation.
+  `select_into` requests a bitmap only for the terminal BAPI assignment sink.
+- Removed the unused all-ones alpha allocation. Positive hours are checked
+  at binding so every subset/group fits I64 despite the kernel's wrapping sum.
+- A rotation changes coordinate-to-ordinal references; it does not transpose
+  carrier storage. The existing BAPI ordinal permutation is an edge read map.
+- SAP tests pass across 0/1/63/64/65/131/4097 inputs, against independent
+  arithmetic and the substrate reference interpreter; repeat resets, bounded
+  scratch, zero hot allocations and original-assignment boundary selection.
+  Strict SAP clippy passes. No nanosecond performance claim is made.
+- Inventory: isolated `lance-graph-sap` consumer contains source descriptors,
+  `CatsSchema: ClassView`, column binding to existing `LaneRef`, cold codebooks,
+  Quack orchestration and explicit C#/hash/BAPI sinks. No SAP execution engine.
+
 ## 2026-09-14 (5) — the ceiling guard CodeRabbit found on the fold commit, and a falsifier that tracked its own constant
 
 **The finding, against `061d12b` (post-fold, not the reviewed `687042f`).**

.claude/board/LATEST_STATE.md

@@ -1,3 +1,22 @@
+## 2026-09-22 — SAP/CATS fold-first dependency stack (PR #1257, unmerged)
+
+- Substrate: ndarray #318 `d0376505`; lance-graph #1256 `4d27032e`.
+  #1246 and #1247 are already ancestors. SAP CI pins the ndarray commit.
+- `CatsQuery` lowers one `Agg::GroupSumI32` through Quack. Bounded tile
+  scratch remains; no population bitmap is retained by binding or aggregation.
+  `select_into` requests a bitmap only for the terminal BAPI assignment sink.
+- Removed the unused all-ones alpha allocation. Positive hours are checked
+  at binding so every subset/group fits I64 despite the kernel's wrapping sum.
+- A rotation changes coordinate-to-ordinal references; it does not transpose
+  carrier storage. The existing BAPI ordinal permutation is an edge read map.
+- SAP tests pass across 0/1/63/64/65/131/4097 inputs, against independent
+  arithmetic and the substrate reference interpreter; repeat resets, bounded
+  scratch, zero hot allocations and original-assignment boundary selection.
+  Strict SAP clippy passes. No nanosecond performance claim is made.
+- Inventory: isolated `lance-graph-sap` consumer contains source descriptors,
+  `CatsSchema: ClassView`, column binding to existing `LaneRef`, cold codebooks,
+  Quack orchestration and explicit C#/hash/BAPI sinks. No SAP execution engine.
+
 ## 2026-09-19 (3) — PR #1252 merged (`8545a555`); `main` is `8545a555`
 
 - **Docs only, no contract inventory delta.** Ruling now on `main`: *we think

.claude/board/entries/2026-09-22-e-cats-fold-does-not-retain-a-population-bitmap-1.md

@@ -0,0 +1,21 @@
+## 2026-09-22 — E-CATS-FOLD-DOES-NOT-RETAIN-A-POPULATION-BITMAP-1 — CATS aggregate lowers to one tiled grouped terminal; bitmap realization is a requested boundary sink
+
+## 2026-09-22 — SAP/CATS fold-first dependency stack (PR #1257, unmerged)
+
+- Substrate: ndarray #318 `d0376505`; lance-graph #1256 `4d27032e`.
+  #1246 and #1247 are already ancestors. SAP CI pins the ndarray commit.
+- `CatsQuery` lowers one `Agg::GroupSumI32` through Quack. Bounded tile
+  scratch remains; no population bitmap is retained by binding or aggregation.
+  `select_into` requests a bitmap only for the terminal BAPI assignment sink.
+- Removed the unused all-ones alpha allocation. Positive hours are checked
+  at binding so every subset/group fits I64 despite the kernel's wrapping sum.
+- A rotation changes coordinate-to-ordinal references; it does not transpose
+  carrier storage. The existing BAPI ordinal permutation is an edge read map.
+- SAP tests pass across 0/1/63/64/65/131/4097 inputs, against independent
+  arithmetic and the substrate reference interpreter; repeat resets, bounded
+  scratch, zero hot allocations and original-assignment boundary selection.
+  Strict SAP clippy passes. No nanosecond performance claim is made.
+- Inventory: isolated `lance-graph-sap` consumer contains source descriptors,
+  `CatsSchema: ClassView`, column binding to existing `LaneRef`, cold codebooks,
+  Quack orchestration and explicit C#/hash/BAPI sinks. No SAP execution engine.
+

.claude/board/entries/README.md

@@ -25,10 +25,11 @@ index row, (3) no duplicate entry id. Checks 1 and 2 are deliberately
 opposite directions; the stranding this convention prevents shows up in
 exactly one of them, never both.
 
-144 entries, 2026-08-06 .. 2026-08-31.
+145 entries, 2026-08-06 .. 2026-09-22.
 
 | date | entry id | finding | file |
 |---|---|---|---|
+| 2026-09-22 | `E-CATS-FOLD-DOES-NOT-RETAIN-A-POPULATION-BITMAP-1` | CATS aggregate lowers to one tiled grouped terminal; bitmap realization is a requested boundary sink | [2026-09-22-e-cats-fold-does-not-retain-a-population-bitmap-1.md](2026-09-22-e-cats-fold-does-not-retain-a-population-bitmap-1.md) |
 | 2026-08-31 | `E-Q8-THE-SIX-DOES-NO-WORK-A-DEGREE-ABLATION-COLLAPSES-THE-HEX-OVERLAYS-ENTIRE-ADVANTAGE-1` | B passes every pre-registered gate and the pass is unattributable: at degree 1 it scores identically with 5.5× less memory | [2026-08-31-e-q8-the-six-does-no-work-a-degree-ablation-collapses-the-hex-overlays-entire-advantage-1.md](2026-08-31-e-q8-the-six-does-no-work-a-degree-ablation-collapses-the-hex-overlays-entire-advantage-1.md) |
 | 2026-08-27 | `E-THE-FUSED-PAYLOAD-IS-INERT-AT-EVERY-EXECUTION-GATE-THAT-CONSUMES-IT-1` |  | [2026-08-27-e-the-fused-payload-is-inert-at-every-execution-gate-that-consumes-it-1.md](2026-08-27-e-the-fused-payload-is-inert-at-every-execution-gate-that-consumes-it-1.md) |
 | 2026-08-26 | `E-THE-PERTURBATION-FIELD-NEVER-REACHED-THE-MASK-ALU-1` | the three DTOs are an adapter seam, not an ALU chain: PerturbationDto.energy is dropped, top_k collapses to a min/max window, and the p64 mask ALU is DTO-blind; 4096==4096 is not an address identity (S/4×O/4 vs codebook) — probe gate filed | [2026-08-26-e-the-perturbation-field-never-reached-the-mask-alu-1.md](2026-08-26-e-the-perturbation-field-never-reached-the-mask-alu-1.md) |

.github/workflows/sap-cats-abi.yml

@@ -0,0 +1,39 @@
+name: SAP CATS ABI
+on:
+  pull_request:
+    paths:
+      - 'crates/lance-graph-sap/**'
+      - 'crates/lance-graph-quack/**'
+      - 'crates/lance-graph-mask-risc/**'
+      - 'crates/lance-graph-contract/**'
+      - '.github/workflows/sap-cats-abi.yml'
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  cats:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          path: lance-graph
+          persist-credentials: false
+      - uses: actions/checkout@v4
+        with:
+          repository: AdaWorldAPI/ndarray
+          ref: master
+          path: ndarray
+          persist-credentials: false
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+      - name: Record tested substrate
+        run: git -C ndarray rev-parse HEAD
+      - name: Format
+        run: cargo +stable fmt --manifest-path lance-graph/crates/lance-graph-sap/Cargo.toml -- --check
+      - name: Lint
+        run: cargo +stable clippy --manifest-path lance-graph/crates/lance-graph-sap/Cargo.toml --all-targets -- -D warnings
+      - name: ABI and boundary tests
+        run: cargo +stable test --manifest-path lance-graph/crates/lance-graph-sap/Cargo.toml
+      - name: Executable CATS slice
+        run: cargo +stable run --manifest-path lance-graph/crates/lance-graph-sap/Cargo.toml --example cats

Cargo.toml

@@ -27,6 +27,7 @@ members = [
     "crates/lance-graph-hydrate",
 ]
 exclude = [
+    "crates/lance-graph-sap",
     # Python bindings (upstream-inherited, opt-in via --manifest-path)
     "crates/lance-graph-python",
     "crates/lance-graph-codec-research",

crates/lance-graph-sap/.gitignore

@@ -0,0 +1,3 @@
+/target/
+/tools/csharp/bin/
+/tools/csharp/obj/

crates/lance-graph-sap/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "lance-graph-sap"
+version = "0.1.0"
+edition = "2021"
+publish = false
+description = "Source-pinned CATS boundary adapters over ClassView and Quack"
+
+[workspace]
+
+[dependencies]
+lance-graph-contract = { path = "../lance-graph-contract" }
+lance-graph-mask-risc = { path = "../lance-graph-mask-risc" }
+lance-graph-quack = { path = "../lance-graph-quack" }
+hmac = "0.12"
+sha2 = "0.10"

crates/lance-graph-sap/examples/cats.rs

@@ -0,0 +1,40 @@
+//! Run: cargo run --manifest-path crates/lance-graph-sap/Cargo.toml --example cats
+use lance_graph_sap::{bind::CatsBatch, edge::*, query::CatsQuery, schema::CatsSchema};
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let fields: Vec<_> = include_str!("../fixtures/cats.txt")
+        .lines()
+        .map(|s| if s == "\\N" { None } else { Some(s) })
+        .collect();
+    let mut input: [Vec<_>; 23] = std::array::from_fn(|i| vec![fields[i]; 4]);
+    input[5][3] = Some("00000007");
+    input[11][2] = Some("OPS");
+    input[10][2] = Some("0.125");
+    input[20] = vec![Some("123456789012345678901234567890123456789012345678901234567890"); 4];
+    let batch = CatsBatch::bind(
+        CatsSchema::new(42, 0),
+        std::array::from_fn(|i| input[i].as_slice()),
+    )?;
+    let mut query = CatsQuery::prepare(&batch, "00000042", "2026-09-01", "2026-09-30")?;
+    let mut sums = vec![0; query.groups()];
+    query
+        .execute_into(&mut sums)
+        .map_err(|e| format!("execution: {e:?}"))?;
+    let mut kept = vec![0; batch.len().div_ceil(64)];
+    query
+        .select_into(&mut kept)
+        .map_err(|e| format!("selection: {e:?}"))?;
+    println!("Exact scale: {}", batch.scale());
+    for total in activity_totals(&batch, &sums)? {
+        println!("{} = {} hours", total.activity_type, total.hours);
+    }
+    let records = bapi_sink(&batch, &kept)?;
+    println!(
+        "{}: {} selected original assignments",
+        BAPI_FUNCTION,
+        records.len()
+    );
+    for record in records {
+        println!("{record:?}");
+    }
+    Ok(())
+}

crates/lance-graph-sap/examples/oracle.rs

@@ -0,0 +1,21 @@
+use lance_graph_sap::{bind::CatsBatch, edge::*, schema::CatsSchema};
+fn main() {
+    let values: Vec<_> = include_str!("../fixtures/cats.txt")
+        .lines()
+        .map(|v| if v == "\\N" { None } else { Some(v) })
+        .collect();
+    let columns: [_; 23] = std::array::from_fn(|i| [values[i]]);
+    let batch = CatsBatch::bind(
+        CatsSchema::new(42, 0),
+        std::array::from_fn(|i| columns[i].as_slice()),
+    )
+    .unwrap();
+    for value in csharp_fields(&batch, 0).unwrap() {
+        println!("{}", value.as_deref().unwrap_or("\\N"));
+    }
+    let projection = ordered_hash_projection(&batch, 0, HashProfile::SmbMiddleware).unwrap();
+    println!(
+        "{projection}\n{}",
+        hash_projection(&projection, b"fixture-key")
+    );
+}

crates/lance-graph-sap/fixtures/cats.txt

@@ -0,0 +1,23 @@
+entry-1
+SAP
+BillableHours
+100
+2026-09-01T12:34:56Z
+00000042
+0000000123
+WBS-1
+000000000123
+2026-09-01T00:00:00Z
+8.50
+DEV
+Billable
+2026-09-01T00:00:00Z
+2026-09-01T02:00:00+02:00
+Valid
+\N
+true
+fixture-hash
+GDPR
+fixture note
+\N
+\N