Preserve subfolder path when uploading google drive images

[bryanbcook]

Needs verification, but I suspect that if you had ![image](folder/image.png) in your markdown, the image would be uploaded as image.png.

This could create some confusion when uploading images to google drive as it will reuse the file name if it's already present. Consider adapting the upload logic to determine the relative path and then recursively create subfolders in google drive when uploading.

Example:

Files:

• c:\dev\blog\attachments\subfolder\image.png
• c:\dev\blog\posts\2025\file.md

Content:

---
title: ...
postid: ...
---
Here is an image ![image](attachments/subfolder/image.png)

cd c:\dev\blog
Import-Module PSBlogger
Publish-MarkdownBloggerPost -File .\posts\2025\file.md -AttachmentsDir .\attachments

Should upload images to <app-folder>/subfolder/image.png

[bryanbcook]

Related to #6 - Google Drive has loose support for hierarchy, allowing files to have parent folder ids. It's loose in that folder names are not unique, and although rare, files can have multiple parent folders.

The Google Drive API supports querying by folder-id, but these results are limited to that folder only. There is no recursive query support.

Related to the auth/drive.file scope, when we want to determine if the file already exists, we should query all files that we can see with our scope, and then establish the logical file path by recursively obtaining the parent folder ids. A smart strategy would be to query all folders that we can see with the auth/drive.file scope, and then construct a lookup table that can be used to help establish the full path. Likewise, when uploading new files this map would help us to determine if the subfolder already exists or if it would need to be created.