fix: large file uploads OOM on memory-constrained devices (Jetson)

Switch multer from memoryStorage to diskStorage for the /batch upload
endpoint. Previously, the entire file was buffered in RAM during upload,
causing Node.js to OOM or crash at ~50% on a 100MB file on Jetson.

Now uploads stream to a temp directory on disk. The file is read into
memory only briefly when passing to IPFS for CID generation. Temp files
are cleaned up after processing.

Also bumps max file size from 100MB to 500MB.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: SashaMIT

pc2-node/src/api/index.ts

@@ -1,6 +1,9 @@
 import express, { Express, Request, Response, NextFunction } from 'express';
 import cookieParser from 'cookie-parser';
 import multer from 'multer';
+import os from 'os';
+import path from 'path';
+import fs from 'fs';
 import { DatabaseManager, FilesystemManager } from '../storage/index.js';
 import { Config } from '../config/loader.js';
 import { Server as SocketIOServer } from 'socket.io';
@@ -395,11 +398,22 @@ export function setupAPI(app: Express): void {
   app.get('/df', authenticate, handleDF);
   app.post('/df', authenticate, handleDF);
 
-  // Batch endpoint with multer for multipart file uploads
+  // Batch endpoint with multer for multipart file uploads.
+  // Uses diskStorage to stream uploads to a temp dir instead of buffering
+  // entirely in RAM -- critical for large files on memory-constrained devices.
+  const uploadTmpDir = path.join(os.tmpdir(), 'pc2-uploads');
+  if (!fs.existsSync(uploadTmpDir)) fs.mkdirSync(uploadTmpDir, { recursive: true });
+
   const upload = multer({ 
-    storage: multer.memoryStorage(),
+    storage: multer.diskStorage({
+      destination: uploadTmpDir,
+      filename: (_req, file, cb) => {
+        const unique = `${Date.now()}-${Math.random().toString(36).slice(2)}`;
+        cb(null, `${unique}-${file.originalname}`);
+      },
+    }),
     limits: {
-      fileSize: 100 * 1024 * 1024 // 100MB max file size
+      fileSize: 500 * 1024 * 1024 // 500MB max file size
     }
   });
 

pc2-node/src/api/info.ts

@@ -446,8 +446,13 @@ export async function handleBatch(req: AuthenticatedRequest, res: Response): Pro
             // Normalize the path (remove double slashes, etc.)
             filePath = filePath.replace(/\/+/g, '/');
 
-            // Get file content - prioritize buffer, fallback to data
-            const fileContent = file.buffer || file.data;
+            // Get file content - buffer (memoryStorage), data, or read from disk (diskStorage)
+            let fileContent = file.buffer || file.data;
+            if (!fileContent && file.path) {
+              const { readFileSync, unlinkSync } = await import('fs');
+              fileContent = readFileSync(file.path);
+              try { unlinkSync(file.path); } catch { /* cleanup best-effort */ }
+            }
             const reportedSize = file.size || (fileContent ? fileContent.length : 0);
             const actualSize = fileContent ? (Buffer.isBuffer(fileContent) ? fileContent.length : (fileContent instanceof Uint8Array ? fileContent.length : Buffer.byteLength(fileContent))) : 0;
 
@@ -578,9 +583,16 @@ export async function handleBatch(req: AuthenticatedRequest, res: Response): Pro
               filePath
             });
 
+            let singleFileContent = file.buffer || file.data;
+            if (!singleFileContent && file.path) {
+              const { readFileSync, unlinkSync } = await import('fs');
+              singleFileContent = readFileSync(file.path);
+              try { unlinkSync(file.path); } catch { /* cleanup best-effort */ }
+            }
+
             const metadata = await filesystem.writeFile(
               filePath,
-              file.buffer || file.data,
+              singleFileContent,
               req.user.wallet_address,
               {
                 mimeType: file.mimetype || file.type