New GUI: Finnish translation

[tgreenx]

Purpose

This PR adds Finnish translation strings for both the messages and the FAQ for the new GUI.
Note that this translation was AI generated. -> reviewed by translator @samisalmensuo

Context

#500

Changes

• Message strings
• FAQ strings

How to test this PR

Review.

[matsduf]

I do not speak Finnish, but I see no issue.

[samisalmensuo]

Request changes (language and terminology improvements for Finnish translation):

Several parts of the Finnish text use wording that is either unnatural, overly literal, or misleading in technical context. In particular:

The term “tuomio” carries legal connotations (“judgement/verdict”) and is not appropriate for DNS testing output.
Multiple FAQ entries and explanatory texts have been rewritten for better readability, technical precision, and consistency.

Terminology has been aligned.

The proposed changes are strictly linguistic and terminological improvements only. No technical meaning has been altered. These updates significantly improve the quality, clarity, and professional tone of the Finnish localization.

[matsduf]

@samisalmensuo, thank you for your feedback! For the FAQ files you have provided new translation. It looks like those translation completely replace the AI translation. Can you confirm that we can just take your translations instead of the ones in the files?

When it comes to the messages, could you provide direct updates of the incorrect translations?

1. In the PR click on "Files changed"
2. Select fi.json
3. When there is a line that needs update (only consider lines with green or white background) move the cursor so that you get a blue cross. Click on that.
4. You get a small window with a menu, "write", "preview" and an icon with "+" above "-". Click on that.
5. Now you can change the text. Do not change the tag to the left. Update the text to the right. Keep quote marks, as they must be there to be valid JSON.
6. Click in "start a review".
7. Continue with next line and do the same and click on "add review comment"
8. When you are done, click on "submit a review" at the top.

[samisalmensuo]

improvements

[samisalmensuo]

improvements

Sami's suggestions should be accepted first.

[tgreenx]

@samisalmensuo thank you for your contribution! I should have incorporated all of your suggestions. If everything looks fine to you now, please approve and we will merge.

[matsduf]

Thanks, @samisalmensuo!