As a software engineer
I want to provide a target path (for each file) when uploading files to public archive via REST API
So that I can more easily update more complex public archives with file tree structures

Given both POST and PUT to /anttp-0/multipart/public_archive are already supported
When choosing to upload one or more files
Then accept an optional target-path field with each file, which accepts a relative target path
And the target-path should be sanitised to avoid any dangerous directory traversals

Given public_archive_service.rs has a function update_archive() for uploading data as public archives
When new files are uploaded
Then when preparing the archive using temporary files, then ensure the directory structure reflects target-path (relative to base directory) 
Then when public_archive.add_file() is called, provide the target-path with the file name, to create the file at the correct location, using the temporary directory structure as a guide

Implementation Notes

- Place any unit tests at the bottom of the same file as the associated production code
- Increment patch version of anttp package in Cargo.toml
- Create a copy of this issue description and save to /spec using the name of this issue as the filename (with lower underscore case, starting with the 5 char padded issue number, e.g. 00001_issue_title.txt)
- Integrate support with MCP tools and gRPC if necessary
- Ensure paths are sanitised to avoid security vulnerabilities, especially during upload to the temporary directory
- Update documentation and postman collection to reflect the new behaviour
- It looks like the target-path array elements are not matching the files array. Validate this and test.
- When providing 2 files, with matching 2 paths, all of the paths are prefixed to the first file path, with commas. This is creating an invalid path for the first file and no path for the second file. File 1 should have path 1 prefixed and file 2 should have path 2 prefixed. Please fix this.
- Fixed a bug where Swagger UI (and potentially other clients) provides `target_path` as a single comma-separated string instead of multiple form fields. The parsing logic now correctly splits these strings to associate paths with their respective files.

swagger UI is generating this POST providing 2 files and 2 associated target_paths:

curl -X 'POST' \
  'http://localhost:18888/anttp-0/multipart/public_archive' \
  -H 'accept: application/json' \
  -H 'x-store-type: memory' \
  -H 'Content-Type: multipart/form-data' \
  -F 'files=@bookmarks.json;type=application/json' \
  -F 'files=@access_list.json;type=application/json' \
  -F 'target_path=bookmarks,access'

then it is creating:

Creating temporary file for archive: "/tmp/f586ffa6-2b67-42a1-86a2-28cbf1260fd2/bookmarks,access/bookmarks.json"
Creating temporary file for archive: "/tmp/f586ffa6-2b67-42a1-86a2-28cbf1260fd2/access_list.json"

but this should be:

Creating temporary file for archive: "/tmp/f586ffa6-2b67-42a1-86a2-28cbf1260fd2/bookmarks/bookmarks.json"
Creating temporary file for archive: "/tmp/f586ffa6-2b67-42a1-86a2-28cbf1260fd2/access/access_list.json"

Correct either the swagger UI schema or the parsing routing to correctly provide or process the form elements as expected.