fix: flush Hocuspocus document to disk before publish

openDirectConnection retrieves the live Y.Doc from Hocuspocus and
writes it to data/<doc>.yjs so the publisher always finds the file,
even when Hocuspocus hasn't triggered a store callback yet.

Made-with: Cursor

backend/src/server.ts

@@ -8,6 +8,7 @@ import { join, dirname } from "path";
 import { fileURLToPath } from "url";
 import { randomUUID } from "crypto";
 import multer from "multer";
+import * as Y from "yjs";
 import { handleChat } from "./agent/chat.js";
 import { citationsRouter } from "./citations.js";
 import {
@@ -168,6 +169,16 @@ app.post("/api/publish", async (req, res) => {
   }
 
   try {
+    // Flush live Hocuspocus document to disk so the publisher can read it
+    const conn = await hocuspocus.openDirectConnection(DEFAULT_DOC_NAME);
+    if (conn.document) {
+      writeFileSync(
+        docPath(DEFAULT_DOC_NAME),
+        Buffer.from(Y.encodeStateAsUpdate(conn.document)),
+      );
+    }
+    await conn.disconnect();
+
     const result = await publishDocument(DEFAULT_DOC_NAME);
     if (!result.success) {
       res.status(500).json({ error: result.error || "Publish failed" });