chore(parser): pin shared PromQL parser revision

crates/frontend-promql/Cargo.toml

@@ -8,10 +8,10 @@ edition = "2021"
 [dependencies]
 asap-types = { path = "../types" }
 
-# ProjectASAP's pinned parser is the shared parser contract used by the backend
-# and control plane. It carries the evaluated PromQL extensions documented in
-# `promql.rs`; syntax outside that contract must fail closed at adapters.
-promql-parser = { git = "https://github.com/ProjectASAP/promql-parser", rev = "c51beafb361af4cc95ed62ae377862c660ceb757" }
+# Shared ProjectASAP parser contract. Keep this immutable revision aligned
+# with backend parsing and treat newly parsed functions as unsupported until
+# the frontend lowerer gives them an explicit semantic mapping.
+promql-parser = { git = "https://github.com/ProjectASAP/promql-parser", rev = "d7606436bde05efe19c5398fe2122faa49062f7d" }
 
 [dev-dependencies]
 asap-aware-mapping = { path = "../asap-aware-mapping" }

crates/frontend-promql/tests/promql_lowering.rs

@@ -18,6 +18,24 @@ fn lower(q: &str) -> QueryExpr {
     lower_promql(q, AccuracyTarget::Exact).unwrap_or_else(|e| panic!("lower failed for {q:?}: {e}"))
 }
 
+#[test]
+fn newly_parsed_metricsql_reducers_fail_closed_without_lowering_semantics() {
+    for query in [
+        "distinct_over_time(cpu_usage[5m])",
+        "entropy_over_time(cpu_usage[5m])",
+    ] {
+        promql_parser::parser::parse(query)
+            .unwrap_or_else(|error| panic!("pinned parser must accept {query:?}: {error}"));
+        assert!(
+            matches!(
+                lower_promql(query, AccuracyTarget::Exact),
+                Err(LoweringError::UnsupportedFunction(_))
+            ),
+            "{query:?} must remain exact-only until the lowerer defines its semantics"
+        );
+    }
+}
+
 // ── Bare selectors & label matchers (folded onto Scan.predicates) ───────────────
 
 #[test]