Refactor PDF conversion utilities for dynamic imports and option handling

- Replace static imports with dynamic imports using a helper function to improve compatibility with pkg snapshots.
- Simplify options handling by destructuring parameters, enhancing readability and maintainability.
- Update image processing logic to utilize destructured width and height options for resizing.

src/pdfUtils.js

@@ -2,35 +2,47 @@
  * PDF conversion utilities loaded on demand so headless startup
  * does not require ESM-only pdf-to-img at module load time.
  */
+import { createRequire } from 'node:module'
+import { pathToFileURL } from 'node:url'
+
+const require = createRequire(import.meta.url)
+
+// Bare dynamic import() fails in pkg snapshots with "Invalid host defined options".
+async function importPackage(name) {
+  const packagePath = require.resolve(name)
+  return import(pathToFileURL(packagePath).href)
+}
+
 export async function convertPDFToImage(pdfInput, options = {}) {
   const [{ pdf }, sharp] = await Promise.all([
-    import('pdf-to-img'),
+    importPackage('pdf-to-img'),
-    import('sharp')
+    importPackage('sharp')
   ])
 
   try {
-    let scale = options.scale || 2
+    const { width, height, page_numbers, scale = 2, ...pdfOnlyOptions } =
+      options
 
     const pdfOptions = {
       scale,
-      ...options
+      ...pdfOnlyOptions
     }
 
     const document = await pdf(pdfInput, pdfOptions)
     const outputImages = []
 
     if (
-      options.page_numbers &&
+      page_numbers &&
-      Array.isArray(options.page_numbers) &&
+      Array.isArray(page_numbers) &&
-      options.page_numbers.length > 0
+      page_numbers.length > 0
     ) {
-      for (const pageNum of options.page_numbers) {
+      for (const pageNum of page_numbers) {
         let image = await document.getPage(pageNum)
 
-        if (options.width || options.height) {
+        if (width || height) {
           const resizeOptions = {}
-          if (options.width) resizeOptions.width = options.width
+          if (width) resizeOptions.width = width
-          if (options.height) resizeOptions.height = options.height
+          if (height) resizeOptions.height = height
           image = await sharp.default(image).resize(resizeOptions).toBuffer()
         }
 
@@ -40,10 +52,10 @@ export async function convertPDFToImage(pdfInput, options = {}) {
       for await (const image of document) {
         let processedImage = image
 
-        if (options.width || options.height) {
+        if (width || height) {
           const resizeOptions = {}
-          if (options.width) resizeOptions.width = options.width
+          if (width) resizeOptions.width = width
-          if (options.height) resizeOptions.height = options.height
+          if (height) resizeOptions.height = height
           processedImage = await sharp.default(image)
             .resize(resizeOptions)
             .toBuffer()