fix(db): batch signal snapshot target lookups

src/db/repositories.ts

@@ -4127,8 +4127,10 @@ export async function listSignalSnapshots(env: Env, signalType: string, targetKe
   return rows.map(toSignalSnapshotRecord);
 }
 
+const SIGNAL_SNAPSHOT_TARGET_KEY_SQL_BATCH = 90;
+
 /** Bulk variant of `listSignalSnapshots` for callers that need the LATEST snapshot per target key across many
- *  keys in one round trip (#3202 review finding: a per-repo loop here made the daily repo-doc refresh sweep
+ *  keys in bounded round trips (#3202 review finding: a per-repo loop here made the daily repo-doc refresh sweep
  *  scale linearly in DB round trips with the installed-repo count). Keyed by the exact `targetKey` string, same
  *  casing convention as `listSignalSnapshots` -- callers that key by lowercased repo name must lowercase both
  *  the input and the returned map's keys themselves. */
@@ -4139,31 +4141,34 @@ export async function listLatestSignalSnapshotsForTargets(
 ): Promise<Map<string, SignalSnapshotRecord>> {
   const result = new Map<string, SignalSnapshotRecord>();
   if (targetKeys.length === 0) return result;
-  const placeholders = targetKeys.map(() => "?").join(", ");
-  const { results } = await env.DB.prepare(
-    `
-      SELECT id, signal_type, target_key, repo_full_name, generated_at
-      FROM (
-        SELECT
-          id, signal_type, target_key, repo_full_name, generated_at,
-          row_number() OVER (PARTITION BY target_key ORDER BY generated_at DESC, id DESC) AS snapshot_rank
-        FROM signal_snapshots
-        WHERE signal_type = ? AND target_key IN (${placeholders})
-      )
-      WHERE snapshot_rank = 1
-    `,
-  )
-    .bind(signalType, ...targetKeys)
-    .all<{ id: string; signal_type: string; target_key: string; repo_full_name: string | null; generated_at: string }>();
-  for (const row of results) {
-    result.set(row.target_key, {
-      id: row.id,
-      signalType: row.signal_type,
-      targetKey: row.target_key,
-      repoFullName: row.repo_full_name,
-      payload: {},
-      generatedAt: row.generated_at,
-    });
+  for (let i = 0; i < targetKeys.length; i += SIGNAL_SNAPSHOT_TARGET_KEY_SQL_BATCH) {
+    const batch = targetKeys.slice(i, i + SIGNAL_SNAPSHOT_TARGET_KEY_SQL_BATCH);
+    const placeholders = batch.map(() => "?").join(", ");
+    const { results } = await env.DB.prepare(
+      `
+        SELECT id, signal_type, target_key, repo_full_name, generated_at
+        FROM (
+          SELECT
+            id, signal_type, target_key, repo_full_name, generated_at,
+            row_number() OVER (PARTITION BY target_key ORDER BY generated_at DESC, id DESC) AS snapshot_rank
+          FROM signal_snapshots
+          WHERE signal_type = ? AND target_key IN (${placeholders})
+        )
+        WHERE snapshot_rank = 1
+      `,
+    )
+      .bind(signalType, ...batch)
+      .all<{ id: string; signal_type: string; target_key: string; repo_full_name: string | null; generated_at: string }>();
+    for (const row of results) {
+      result.set(row.target_key, {
+        id: row.id,
+        signalType: row.signal_type,
+        targetKey: row.target_key,
+        repoFullName: row.repo_full_name,
+        payload: {},
+        generatedAt: row.generated_at,
+      });
+    }
   }
   return result;
 }

test/unit/data-spine.test.ts

@@ -512,4 +512,43 @@ describe("listLatestSignalSnapshotsForTargets (#3202 — bulk latest-per-target
     expect(result.get("owner/b")).toMatchObject({ id: "b-only", generatedAt: "2026-03-01T00:00:00.000Z" });
     expect(result.has("owner/c")).toBe(false);
   });
+
+  it("batches target-key lookups to stay under D1 bound-parameter limits", async () => {
+    const env = createTestEnv();
+    const targetKeys = Array.from({ length: 95 }, (_, index) => `owner/repo-${index}`);
+    for (const [index, targetKey] of targetKeys.entries()) {
+      await persistSignalSnapshot(env, {
+        id: `batched-${index}`,
+        signalType: "repo-doc-refresh-attempt",
+        targetKey,
+        payload: {},
+        generatedAt: `2026-06-01T00:${String(index).padStart(2, "0")}:00.000Z`,
+      });
+    }
+    const db = env.DB;
+    const boundCounts: number[] = [];
+    env.DB = {
+      ...db,
+      prepare(sql: string) {
+        const statement = db.prepare(sql);
+        return {
+          ...statement,
+          bind(...values: Parameters<typeof statement.bind>) {
+            if (sql.includes("FROM signal_snapshots") && sql.includes("target_key IN")) {
+              boundCounts.push(values.length);
+              if (values.length > 91) throw new Error(`too many bound parameters: ${values.length}`);
+            }
+            return statement.bind(...values);
+          },
+        };
+      },
+    } as D1Database;
+
+    const result = await listLatestSignalSnapshotsForTargets(env, "repo-doc-refresh-attempt", targetKeys);
+
+    expect(result.size).toBe(95);
+    expect(result.get("owner/repo-0")?.id).toBe("batched-0");
+    expect(result.get("owner/repo-94")?.id).toBe("batched-94");
+    expect(boundCounts).toEqual([91, 6]);
+  });
 });