How to create a stuffed textblock

There is a need to create a page layout that is filled to it cannot be “changed”
The Page should be filled.

Any sentence that is not equal to the total width needs to filled as well.

The text needs to be mono spaced font, and the page needs to be filled.
with single space between the words. Left justified.
Example:

this is an example text
where there is a-------
filling until s the end
of a line--------------
-----------------------
1. item list-----------
2. also has filling----

Any empty line needs to be filled until the right page margin.

To the best of my knowledge, this can’t be done presently with styles. There is a weak solution for the last line where you could type a tab after the last character. Tab stop would be set at right margin with a dash to create a leading line. However, this does nothing for the intermediate lines in the paragraph.

I assume you’re preparing some legal paper where no addition must be possible after printing. You could have a look to numerically signed documents (both odt and pdf), but this does not show on a print.

You guessed right, the crux is the document is not electronic, it is the print that needs the guard.
It just needs to be prepared in libreoffice…
I couldn’t find it, so i have to guess it currently can’t be done other than by hand add dashes.
The tab would add the same issue as it also needs to be inside a sentence. AFAIK no hyphenation is done. Long words also should cause mid sentence dashes.

Maybe something to ad as option to paragraph formatting?

Seems something can be simulated with paragraph options.