feat: add image to PDF converter

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/converters/imageToPdf.js

@@ -0,0 +1,31 @@
+import fs from 'node:fs/promises';
+import sharp from 'sharp';
+import { PDFDocument } from 'pdf-lib';
+import { register } from './registry.js';
+
+const IMAGE_FORMATS = ['jpg', 'jpeg', 'png', 'webp', 'gif', 'tiff', 'avif'];
+
+async function convert(inputPath, outputPath) {
+  const pngBuffer = await sharp(inputPath).png().toBuffer();
+  const metadata = await sharp(pngBuffer).metadata();
+
+  const pdfDoc = await PDFDocument.create();
+  const page = pdfDoc.addPage([metadata.width, metadata.height]);
+  const embeddedImage = await pdfDoc.embedPng(pngBuffer);
+
+  page.drawImage(embeddedImage, {
+    x: 0,
+    y: 0,
+    width: metadata.width,
+    height: metadata.height,
+  });
+
+  const pdfBytes = await pdfDoc.save();
+  await fs.writeFile(outputPath, pdfBytes);
+}
+
+export function registerImageToPdfConverter() {
+  for (const sourceFormat of IMAGE_FORMATS) {
+    register({ family: 'image', sourceFormat, targetFormat: 'pdf', convert });
+  }
+}