perf: compute archive stats off the API thread

src/adminStatsWorker.js

@@ -0,0 +1,33 @@
+const { parentPort, workerData } = require('node:worker_threads');
+const Database = require('better-sqlite3');
+
+try {
+  const db = new Database(workerData.databasePath, { readonly: true, fileMustExist: true });
+  const counts = db.prepare(`
+    SELECT
+      (SELECT COUNT(*) FROM articles) AS total,
+      (SELECT COUNT(*) FROM article_embedding_meta) AS withContent,
+      (SELECT COUNT(*) FROM article_embedding_meta) AS withEmbedding,
+      (SELECT COUNT(*) FROM events) AS eventCount,
+      (SELECT COUNT(*) FROM articles WHERE ingested_at >= datetime('now', '-1 hour')) AS ingestedPerHour,
+      (SELECT COUNT(*) FROM article_embedding_meta WHERE embedded_at >= datetime('now', '-1 hour')) AS contentPerHour
+  `).get();
+  const bySource = db.prepare(`
+    SELECT source, COUNT(*) AS n FROM articles GROUP BY source ORDER BY n DESC
+  `).all();
+  const byStatus = db.prepare(`
+    SELECT COALESCE(content_status, 'null') AS status, COUNT(*) AS n
+    FROM articles GROUP BY content_status ORDER BY n DESC
+  `).all();
+  let embeddingsPerHour = 0;
+  try {
+    embeddingsPerHour = db.prepare(`
+      SELECT COUNT(*) AS n FROM article_embedding_meta
+      WHERE embedded_at >= datetime('now', '-1 hour')
+    `).get().n;
+  } catch (_) {}
+  db.close();
+  parentPort.postMessage({ value: { ...counts, bySource, byStatus, embeddingsPerHour } });
+} catch (error) {
+  parentPort.postMessage({ error: error.message });
+}