refactor: enhance manual chunking in Vite config for better code splitting

src/services/storage-attachment-token-repo.ts

@@ -0,0 +1,46 @@
+type ShouldRunPeriodicCleanup = (lastRunAt: number, intervalMs: number) => boolean;
+
+export async function ensureUsedAttachmentDownloadTokenTable(db: D1Database): Promise<void> {
+  await db
+    .prepare(
+      'CREATE TABLE IF NOT EXISTS used_attachment_download_tokens (' +
+        'jti TEXT PRIMARY KEY, ' +
+        'expires_at INTEGER NOT NULL' +
+        ')'
+    )
+    .run();
+}
+
+export async function consumeAttachmentDownloadToken(
+  db: D1Database,
+  shouldRunPeriodicCleanup: ShouldRunPeriodicCleanup,
+  lastCleanupAt: number,
+  cleanupIntervalMs: number,
+  jti: string,
+  expUnixSeconds: number
+): Promise<{ consumed: boolean; cleanedUpAt: number | null }> {
+  const nowMs = Date.now();
+  let cleanedUpAt: number | null = null;
+
+  if (shouldRunPeriodicCleanup(lastCleanupAt, cleanupIntervalMs)) {
+    await db
+      .prepare('DELETE FROM used_attachment_download_tokens WHERE expires_at < ?')
+      .bind(nowMs)
+      .run();
+    cleanedUpAt = nowMs;
+  }
+
+  const expiresAtMs = expUnixSeconds * 1000;
+  const result = await db
+    .prepare(
+      'INSERT INTO used_attachment_download_tokens(jti, expires_at) VALUES(?, ?) ' +
+        'ON CONFLICT(jti) DO NOTHING'
+    )
+    .bind(jti, expiresAtMs)
+    .run();
+
+  return {
+    consumed: (result.meta.changes ?? 0) > 0,
+    cleanedUpAt,
+  };
+}