refactor(sketch): split asap-sketch out of core (#57, phase 2) (#59)

Phase 2 of the crate reorg (#57): the L4 sketch algebra moves into its own
crate. `core/sketch_algebra/` (expr/schema/sketch) becomes `asap-sketch`,
depending only on the IR crate (the sketch->intent_algebra dep was already
one-directional). Imports rebased onto `asap_control_core::…`; the
`sketch_algebra` module is dropped from `core`.

No external consumers today, so no downstream import churn. No behavior
change; full workspace suite green; clippy --all-targets clean.

Co-authored-by: zz_y <zz_y@node0.zz-y-308294.softmeasure-pg0.clemson.cloudlab.us>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

Cargo.lock

@@ -1,6 +1,7 @@
 [workspace]
 members = [
     "crates/core",
+    "crates/sketch",
     "crates/plan",
     "crates/lower",
     "crates/e2e",

Cargo.toml

@@ -1,4 +1,3 @@
 pub mod intent_algebra;
-pub mod sketch_algebra;
 pub mod types;
 pub mod workload;

crates/core/src/lib.rs

@@ -0,0 +1,9 @@
+[package]
+name = "asap-sketch"
+version = "0.1.0"
+edition = "2021"
+
+# The L4 sketch algebra (sketch-bound IR) over the L3 intent algebra.
+# Depends only on the IR crate.
+[dependencies]
+asap-control-core = { path = "../core" }

crates/core/src/sketch_algebra/mod.rs

@@ -2,7 +2,7 @@ use std::rc::Rc;
 
 use super::schema::L4Schema;
 use super::sketch::{SketchQuery, SummaryKind, SummaryParams};
-use crate::intent_algebra::{ColumnId, ColumnRef, QueryExpr};
+use asap_control_core::intent_algebra::{ColumnId, ColumnRef, QueryExpr};
 
 // ── L4 DAG node ───────────────────────────────────────────────────────────────
 

crates/sketch/Cargo.toml

@@ -0,0 +1,16 @@
+//! `asap-sketch` — the L4 **sketch algebra** (sketch-bound IR) over the L3
+//! intent algebra.
+//!
+//! Where L3 ([`asap_control_core::intent_algebra`]) carries *intent* only
+//! ("compute a quantile to ε accuracy"), this layer is the sketch-bound IR:
+//! the sketch kind + parameters are committed ([`SummaryKind`] /
+//! [`SummaryParams`]), and [`L4Node`] / [`SummaryExpr`] describe the summary
+//! computation. It depends only on the IR crate.
+
+pub mod expr;
+pub mod schema;
+pub mod sketch;
+
+pub use expr::{L4Node, SummaryExpr};
+pub use schema::{L4DataType, L4Field, L4Schema};
+pub use sketch::{SketchQuery, SummaryKind, SummaryParams};

crates/core/src/sketch_algebra/expr.rs crates/sketch/src/expr.rscrates/core/src/sketch_algebra/expr.rs renamed to crates/sketch/src/expr.rs

@@ -1,5 +1,5 @@
 use super::sketch::{SummaryKind, SummaryParams};
-use crate::intent_algebra::DataType;
+use asap_control_core::intent_algebra::DataType;
 
 // ── L4 data types ─────────────────────────────────────────────────────────────
 

crates/sketch/src/lib.rs

@@ -1,4 +1,4 @@
-use crate::intent_algebra::ColumnRef;
+use asap_control_core::intent_algebra::ColumnRef;
 
 // ── Summary kind identifiers ───────────────────────────────────────────────────