v3: code quality pass, various bug fixes

api/services/notification-service.ts

@@ -2,6 +2,7 @@ import type {
   Notification,
   NotificationData,
   NotificationType,
+  UserDumpPostedData,
 } from "../model/interfaces.ts";
 import { APIErrorCode, APIException } from "../model/interfaces.ts";
 import { db, isNotificationRow, notificationRowToApi } from "../model/db.ts";
@@ -156,14 +157,53 @@ export function notifyUserFollowersNewDump(
     `SELECT follower_id FROM follows WHERE followed_user_id = ?;`,
   ).all(dumperId) as { follower_id: string }[];
 
+  if (followerRows.length === 0) return;
+
+  const data: UserDumpPostedData = {
+    dumperId,
+    dumperUsername: posterRow.username,
+    dumpId,
+    dumpTitle,
+  };
+  const dataJson = JSON.stringify(data);
+  const createdAt = new Date().toISOString();
+  const sourceKey = `dump:${dumpId}`;
+
+  // Batch INSERT all follower notifications in a single statement
+  const params: (string | number | null)[] = [];
+  const placeholders: string[] = [];
   for (const row of followerRows) {
-    createNotification(
+    const id = crypto.randomUUID();
+    placeholders.push("(?, ?, ?, ?, 0, ?, ?)");
+    params.push(
+      id,
       row.follower_id,
       "user_dump_posted",
-      { dumperId, dumperUsername: posterRow.username, dumpId, dumpTitle },
-      `dump:${dumpId}`,
+      dataJson,
+      createdAt,
+      sourceKey,
     );
   }
+
+  const result = db.prepare(
+    `INSERT OR IGNORE INTO notifications (id, user_id, type, data, read, created_at, source_key)
+     VALUES ${placeholders.join(", ")};`,
+  ).run(...params);
+
+  if ((result.changes as number) > 0) {
+    for (const row of followerRows) {
+      sendToUser(row.follower_id, {
+        type: "notification_created",
+        notification: {
+          userId: row.follower_id,
+          type: "user_dump_posted",
+          data,
+          read: false,
+          createdAt,
+        },
+      });
+    }
+  }
 }
 
 export function notifyDumpOwnerUpvote(