create a Calc document for each directory
The OpenDocument Spreadsheet would only be one file for all files and folders. Nested inside this spreadsheet can exist hyperlinks to all kinds of files not only other spreadsheets.
The structure of a Calc document is not nested.
The ‘nesting’ can be replicated with using fields in the spreadsheet.
Tellico: Is it able to load a complete tree structure
I do not know Tellico, too. Just searched for some other options.
metadata needs to be filled by someone
Your actual meta data exists in folder names and file names - just perfect to extract them automatically. After extracting the meta data real folder names and file names may be shortened to fit OS limits.
I still think that the KISS answer …
I agree with you to keep it simple but I do not agree with you that your solution is technically as simple as using a spreadsheet …
to adapt limitations in Linux to be irrelevant to “normal computer use”
In my opinion discussed limits of linux are not heavily relevant to “normal computer use”.
My mother is retired, she will turn 76 years old later in 2025 and has habits.
I totally agree with you that any altering of procedures will break your mother’s habits. And I totally understand and appreciate your aim to not touch your mother’s workflow to not confuse her.