fix(javascript): include response carriers in endpoint traces

Include request and response endpoint carriers in the shared semantic query seed matcher so traces retain resolved response consumers, source identities, and incomplete coverage.

Validated with 44 domain tests, compiled CLI/MCP parity, full static/architecture checks, and current-head automated review/CI.

Fixes #4213.

src/domain/javascript/javascriptSemanticGraphQuery.test.ts

@@ -246,6 +246,42 @@ it("matches scalar literal seeds and skips non-scalar literal metadata", () => {
   expect(query("unmatched")).toEqual([]);
 });
 
+it("matches exact endpoint properties on request and response carriers only", () => {
+  const input = semanticFixtureInput();
+  const contexts = new JavaScriptSemanticEvidenceContextRegistry();
+  const endpoint = "https://example.invalid/v1";
+  const response = node("response", "response", { endpoint }, contexts);
+  const other = node(
+    "response",
+    "other-endpoint",
+    { endpoint: `${endpoint}/other` },
+    contexts,
+  );
+  const displayOnly = node("response", endpoint, { endpoint: null }, contexts);
+  input.nodes.push(
+    response,
+    displayOnly,
+    node("response", "missing-endpoint", {}, contexts),
+    other,
+    node("response", "array-endpoint", { endpoint: [endpoint] }, contexts),
+    node("boundary", "unrelated-carrier", { endpoint }, contexts),
+  );
+  const graph = createJavaScriptSemanticGraph(input);
+  const request = input.nodes.find(({ kind }) => kind === "request");
+  if (request === undefined) throw new Error("Expected request carrier");
+  const query = (value: string) =>
+    queryJavaScriptSemanticGraph(graph, {
+      seed: { kind: "endpoint", value },
+      direction: "forward-influence",
+    });
+  expect(query(endpoint).seed_node_ids).toEqual(
+    [request.node_id, response.node_id].toSorted(),
+  );
+  expect(query(`${endpoint}/other`).seed_node_ids).toEqual([other.node_id]);
+  expect(query("response").seed_node_ids).toEqual([]);
+  expect(query(`${endpoint}/missing`).seed_node_ids).toEqual([]);
+});
+
 it("scopes callers unknowns to call relations while preserving graph uncertainty", () => {
   const contexts = new JavaScriptSemanticEvidenceContextRegistry();
   const caller = node("function", "caller", {}, contexts);