I copied some files to my iPhone via ITunes to a specific app by selecting the phone in iTunes, clicking "File Sharing", selecting the app and then dragging and dropping the files into the app. Now those files are in the app but they also show up in the iOS Files App. I don't want them to show up in the Files app. They are private files (password.txt, ssh-key.private.txt, secret-project-planning.txt).
Things I tried
turn off app in Siri and Search -> App Name -> Siri & Suggestions
this removed the files via the app from search on the home screen but not from the Files app. In other words the files all still appear even though the app is hidden.
looked in the Files app for settings
there are no per app settings in the Files app
searched in system settings for "Files"
no matches. Apparently there are no settings for the Files app..
searched in system settings for the apps whos' files I don't want exposed in the Files App
no related settings appeared. Document storage is set to "On My iPhone". "Siri & Search" shows "off"
turn off "Show app" in Siri & Search setting.
This has the ridiculous effect of making the app itself not appear as a search result but the settings for the app still appear as does the app's folder so technically the app is still showing up in search.
How can I get the files not to show up in the Files App?
If you want to repo the issue you can download Firefox
Then go to https://greggman.github.io/doodles/dl.html
Long press the link and pick "Download Link" when it appears
Pick "Download Now" when it appersa
Now go to the "Files App" and pick "Firefox"
Notes the file is visible here
The thumbnails make this issue particularly troublesome as you can read the beginning contents of the files you're trying to make not appear. Even without the thumbnail the filename itself is enough to give something away.
Even worse, everything the Files app sees shows up in the system wide search (drag down on homescreen) so if someone is looking over my shoulder and I use search it's possible they'll see things I was trying to hide
Ideally via some option the app, Firefox, would not even show up in Files but at a minimum I need some option to make the files for a particular app not appear.
Note that MacOS has the option to hide folders from search under Spotlight->Privacy. All I'm asking is how to achieve the same result on iOS