fix(memory): use explicit qmd snippet line metadata (#58181)

* fix(memory): preserve qmd snippet line metadata

* Memory/QMD: preserve snippet span with partial line metadata

packages/memory-host-sdk/src/host/qmd-query-parser.test.ts

@@ -24,6 +24,22 @@ complete`,
     expect(results).toEqual([{ docid: "abc", score: 0.5 }]);
   });
 
+  it("preserves explicit qmd line metadata when present", () => {
+    const results = parseQmdQueryJson(
+      '[{"docid":"abc","score":0.5,"start_line":4,"end_line":6,"snippet":"@@ -10,1\\nignored"}]',
+      "",
+    );
+    expect(results).toEqual([
+      {
+        docid: "abc",
+        score: 0.5,
+        snippet: "@@ -10,1\nignored",
+        startLine: 4,
+        endLine: 6,
+      },
+    ]);
+  });
+
   it("treats plain-text no-results from stderr as an empty result set", () => {
     const results = parseQmdQueryJson("", "No results found\n");
     expect(results).toEqual([]);

packages/memory-host-sdk/src/host/qmd-query-parser.ts

@@ -9,6 +9,8 @@ export type QmdQueryResult = {
   file?: string;
   snippet?: string;
   body?: string;
+  startLine?: number;
+  endLine?: number;
 };
 
 export function parseQmdQueryJson(stdout: string, stderr: string): QmdQueryResult[] {
@@ -73,12 +75,40 @@ function parseQmdQueryResultArray(raw: string): QmdQueryResult[] | null {
     if (!Array.isArray(parsed)) {
       return null;
     }
-    return parsed as QmdQueryResult[];
+    return parsed.map((item) => {
+      if (typeof item !== "object" || item === null) {
+        return item as QmdQueryResult;
+      }
+      const record = item as Record<string, unknown>;
+      const docid = typeof record.docid === "string" ? record.docid : undefined;
+      const score =
+        typeof record.score === "number" && Number.isFinite(record.score)
+          ? record.score
+          : undefined;
+      const collection = typeof record.collection === "string" ? record.collection : undefined;
+      const file = typeof record.file === "string" ? record.file : undefined;
+      const snippet = typeof record.snippet === "string" ? record.snippet : undefined;
+      const body = typeof record.body === "string" ? record.body : undefined;
+      return {
+        docid,
+        score,
+        collection,
+        file,
+        snippet,
+        body,
+        startLine: parseQmdLineNumber(record.start_line ?? record.startLine),
+        endLine: parseQmdLineNumber(record.end_line ?? record.endLine),
+      } as QmdQueryResult;
+    });
   } catch {
     return null;
   }
 }
 
+function parseQmdLineNumber(value: unknown): number | undefined {
+  return typeof value === "number" && Number.isFinite(value) && value > 0 ? value : undefined;
+}
+
 function extractFirstJsonArray(raw: string): string | null {
   const start = raw.indexOf("[");
   if (start < 0) {