feat: download datasheets + manuals to Fearghas NAS in nightly sync

- downloadDocuments(): fetches PDFs from product_documents and documents tables
  using curl, organises into switches/ transceivers/ whitepapers/ other/ subdirs
- Integrated into runNightlyNasSync() — runs after JSON exports
- rsync incremental — only new/changed files transferred
- NAS dir structure: /volume1/tip-data/datasheets/{switches,transceivers,whitepapers,other}
- max-filesize 50MB guard per file

packages/scraper/src/utils/nas-sync.ts

@@ -28,7 +28,7 @@
 
 import { exec } from "child_process";
 import { promisify } from "util";
-import { writeFile, mkdir, rm } from "fs/promises";
+import { writeFile, mkdir, rm, access } from "fs/promises";
 import { join } from "path";
 import { tmpdir } from "os";
 import { db as pool } from "./db";
@@ -253,10 +253,17 @@ export async function runNightlyNasSync(): Promise<void> {
       await createDbBackup(backupDir, date);
     }
 
-    // 4. Sync exports to NAS
+    // 4. Download datasheets / manuals / whitepapers
+    const datasheetDir = join(tmpBase, "datasheets");
+    await downloadDocuments(datasheetDir);
+
+    // 5. Sync exports to NAS
     await rsyncToNas(join(tmpBase, "exports"), "exports");
 
-    // 5. Sync backups if created
+    // 6. Sync datasheets to NAS (incremental — only new files)
+    await rsyncToNas(datasheetDir, "datasheets");
+
+    // 7. Sync backups if created
     if (isBackupDay) {
       await rsyncToNas(backupDir, "db-backups");
     }
@@ -268,11 +275,86 @@ export async function runNightlyNasSync(): Promise<void> {
   }
 }
 
+// ─────────────────────────────────────────────────────────────────────────────
+// Download datasheets, manuals & documents to local dir for NAS sync
+// ─────────────────────────────────────────────────────────────────────────────
+async function downloadDocuments(destDir: string): Promise<number> {
+  await mkdir(destDir, { recursive: true });
+  await mkdir(join(destDir, "switches"),      { recursive: true });
+  await mkdir(join(destDir, "transceivers"),  { recursive: true });
+  await mkdir(join(destDir, "whitepapers"),   { recursive: true });
+  await mkdir(join(destDir, "other"),         { recursive: true });
+
+  let downloaded = 0;
+
+  // 1. product_documents (switch + transceiver datasheets, manuals)
+  const pdRows = await pool.query<{
+    id: string; doc_type: string; title: string;
+    url: string; switch_id: string | null; transceiver_id: string | null;
+  }>(`
+    SELECT id, doc_type, title,
+           COALESCE(download_url, source_url) AS url,
+           switch_id, transceiver_id
+    FROM product_documents
+    WHERE COALESCE(download_url, source_url) IS NOT NULL
+    ORDER BY created_at DESC
+  `);
+
+  // 2. documents table (whitepapers, research)
+  const docsRows = await pool.query<{
+    id: string; doc_type: string; title: string; url: string;
+  }>(`
+    SELECT id, doc_type, title, source_url AS url
+    FROM documents
+    WHERE source_url IS NOT NULL
+    ORDER BY created_at DESC
+  `);
+
+  const allDocs = [
+    ...pdRows.rows.map(r => ({ ...r, source: "product_documents" as const })),
+    ...docsRows.rows.map(r => ({ ...r, switch_id: null, transceiver_id: null, source: "documents" as const })),
+  ];
+
+  for (const doc of allDocs) {
+    if (!doc.url) continue;
+
+    const subdir = doc.switch_id ? "switches"
+      : doc.transceiver_id ? "transceivers"
+      : doc.doc_type === "whitepaper" ? "whitepapers"
+      : "other";
+
+    const safeName = (doc.title || "doc").replace(/[^a-z0-9_\-\.]/gi, "_").slice(0, 80);
+    const ext = doc.url.toLowerCase().includes(".pdf") ? ".pdf" : ".pdf";
+    const filePath = join(destDir, subdir, `${safeName}${ext}`);
+
+    // Skip if already downloaded in this run
+    try { await access(filePath); continue; } catch { /* not cached, download */ }
+
+    try {
+      await execAsync(
+        `curl -sL --max-time 60 --max-filesize 52428800 -A "TIP-DataCollector/1.0" -o "${filePath}" "${doc.url}"`,
+        { timeout: 65000 }
+      );
+      downloaded++;
+      logger.info(`Downloaded: ${subdir}/${safeName}${ext}`);
+    } catch (err) {
+      logger.warn(`Failed to download doc: ${doc.title}`, { url: doc.url, err });
+    }
+  }
+
+  logger.info(`Documents downloaded: ${downloaded}/${allDocs.length}`);
+  return downloaded;
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // Setup NAS directory structure (run once)
 // ─────────────────────────────────────────────────────────────────────────────
 export async function setupNasDirectories(): Promise<void> {
-  const dirs = ["exports", "db-backups", "raw-cache", "logs"];
+  const dirs = [
+    "exports", "db-backups", "raw-cache", "logs",
+    "datasheets", "datasheets/switches", "datasheets/transceivers",
+    "datasheets/whitepapers", "datasheets/other",
+  ];
   for (const dir of dirs) {
     try {
       await execAsync(