test(engine): execution goldens for typed-literal filters (C4 gap #4)

New literal_filters.rs covers filtering by F64/F32/Bool/Date/DateTime LITERALS
across both arms: standalone comparisons ($m.score > 1.5, $m.ratio <= 0.25,
$m.active = true, $m.born >= date(...), $m.seen < datetime(...)) exercise the
in-memory comparison path, and inline bindings (Metric { active: true },
Metric { score: 3.0 }) exercise Lance filter_expr pushdown. Seeds partition each
predicate so a dropped/miscast filter returns all rows. (Param-bound scalars and
list-column contains are covered elsewhere.)

crates/omnigraph/tests/literal_filters.rs

@@ -0,0 +1,96 @@
+//! Execution goldens for filtering by non-string/non-integer scalar LITERALS
+//! (F64, F32, Bool, Date, DateTime), across both the in-memory comparison arm
+//! (standalone `$m.prop op lit`) and the Lance-pushdown arm (inline binding
+//! `Metric { prop: lit }`). Param-bound scalar filters and list-column
+//! `contains` are already covered elsewhere; this closes the literal-RHS gap.
+
+mod helpers;
+
+use arrow_array::{Array, StringArray};
+
+use omnigraph::db::Omnigraph;
+use omnigraph::loader::{LoadMode, load_jsonl};
+use omnigraph_compiler::ir::ParamMap;
+
+use helpers::*;
+
+const SCHEMA: &str = r#"
+node Metric {
+    name: String @key
+    score: F64?
+    ratio: F32?
+    active: Bool?
+    born: Date?
+    seen: DateTime?
+}
+"#;
+
+// Seeds partition every predicate, so a dropped filter returns all 4 rows.
+const DATA: &str = r#"{"type":"Metric","data":{"name":"m1","score":2.5,"ratio":0.5,"active":true,"born":"2024-06-01","seen":"2024-06-01T12:00:00Z"}}
+{"type":"Metric","data":{"name":"m2","score":1.0,"ratio":0.25,"active":false,"born":"2023-01-01","seen":"2023-01-01T00:00:00Z"}}
+{"type":"Metric","data":{"name":"m3","score":3.0,"ratio":0.75,"active":true,"born":"2025-01-01","seen":"2025-01-01T00:00:00Z"}}
+{"type":"Metric","data":{"name":"m4","score":0.5,"ratio":0.1,"active":false,"born":"2022-12-31","seen":"2022-01-01T00:00:00Z"}}"#;
+
+async fn metric_db(dir: &tempfile::TempDir) -> Omnigraph {
+    let uri = dir.path().to_str().unwrap();
+    let mut db = Omnigraph::init(uri, SCHEMA).await.unwrap();
+    load_jsonl(&mut db, DATA, LoadMode::Overwrite).await.unwrap();
+    db
+}
+
+async fn sorted_metric_names(db: &mut Omnigraph, queries: &str, name: &str) -> Vec<String> {
+    let r = query_main(db, queries, name, &ParamMap::new()).await.unwrap();
+    if r.num_rows() == 0 {
+        return Vec::new();
+    }
+    let b = r.concat_batches().unwrap();
+    let col = b.column(0).as_any().downcast_ref::<StringArray>().unwrap();
+    let mut v: Vec<String> = (0..col.len()).map(|i| col.value(i).to_string()).collect();
+    v.sort();
+    v
+}
+
+#[tokio::test]
+async fn float_literal_filters_execute() {
+    let dir = tempfile::tempdir().unwrap();
+    let mut db = metric_db(&dir).await;
+    let q = r#"
+query gt() { match { $m: Metric  $m.score > 1.5 } return { $m.name } }
+query le() { match { $m: Metric  $m.ratio <= 0.25 } return { $m.name } }
+query inline() { match { $m: Metric { score: 3.0 } } return { $m.name } }
+"#;
+    // F64 standalone: scores 2.5, 3.0 > 1.5
+    assert_eq!(sorted_metric_names(&mut db, q, "gt").await, vec!["m1", "m3"]);
+    // F32 standalone: ratios 0.25, 0.1 <= 0.25
+    assert_eq!(sorted_metric_names(&mut db, q, "le").await, vec!["m2", "m4"]);
+    // F64 inline-binding pushdown: score == 3.0
+    assert_eq!(sorted_metric_names(&mut db, q, "inline").await, vec!["m3"]);
+}
+
+#[tokio::test]
+async fn bool_literal_filters_execute() {
+    let dir = tempfile::tempdir().unwrap();
+    let mut db = metric_db(&dir).await;
+    let q = r#"
+query standalone() { match { $m: Metric  $m.active = true } return { $m.name } }
+query inline() { match { $m: Metric { active: true } } return { $m.name } }
+query negated() { match { $m: Metric  $m.active != true } return { $m.name } }
+"#;
+    assert_eq!(sorted_metric_names(&mut db, q, "standalone").await, vec!["m1", "m3"]);
+    assert_eq!(sorted_metric_names(&mut db, q, "inline").await, vec!["m1", "m3"]);
+    assert_eq!(sorted_metric_names(&mut db, q, "negated").await, vec!["m2", "m4"]);
+}
+
+#[tokio::test]
+async fn date_and_datetime_literal_filters_execute() {
+    let dir = tempfile::tempdir().unwrap();
+    let mut db = metric_db(&dir).await;
+    let q = r#"
+query born_ge() { match { $m: Metric  $m.born >= date("2024-01-01") } return { $m.name } }
+query seen_lt() { match { $m: Metric  $m.seen < datetime("2024-01-01T00:00:00Z") } return { $m.name } }
+"#;
+    // born: m1 2024-06, m3 2025 >= 2024-01-01
+    assert_eq!(sorted_metric_names(&mut db, q, "born_ge").await, vec!["m1", "m3"]);
+    // seen: m2 2023, m4 2022 < 2024-01-01
+    assert_eq!(sorted_metric_names(&mut db, q, "seen_lt").await, vec!["m2", "m4"]);
+}