fix: increase OCR timeout and configure Next.js dev origins

- Increased tesseract.js worker creation timeout from 8s → 20s (accounts for lazy loading and language model download on first run)
- Added allowedDevOrigins to next.config.mjs to permit localhost and .local hostnames
- Resolves OCR timeout on slow connections and first-time initialization

frontend/components/Scanner.tsx

@@ -165,7 +165,7 @@ export default function Scanner({ onScanSuccess, onOCRMatch, paused }: ScannerPr
       // Lazy-load tesseract.js only when OCR is actually needed
       const { createWorker } = await import('tesseract.js');
       const workerPromise = createWorker('eng');
-      const timeoutPromise = new Promise((_, reject) => setTimeout(() => reject(new Error("OCR Engine timeout")), 8000));
+      const timeoutPromise = new Promise((_, reject) => setTimeout(() => reject(new Error("OCR Engine timeout")), 20000));
 
       const worker = await Promise.race([workerPromise, timeoutPromise]) as any;
       const dataUrl = canvas.toDataURL('image/jpeg', 0.85);