i18n: Update and fix Japanese translation

[NatsukiOgata]

Hello there!

Make sure you've followed the Contributing guidelines before finalizing your pull request.

TL;DR:

• You're opening this PR against the current release branch
• Works on both Python 2.7 & Python 3.x (JSON only, no code changes)
• Commits have been squashed and includes the relevant issue number
• Pull request description contains link to relevant issue or detailed notes on changes
• This must include example code demonstrating your feature or the bug being fixed
• All existing tests pass
• Your bug fix / feature has associated test coverage
• README.md is updated (if relevant)

---

Description

I have updated the japanese.json file.

Changes:

• Fixed some typos (e.g., corrected "アップリ" to "アプリケーション").
• Standardized UI expressions and resolved wording inconsistencies (e.g., synchronized "必須項目" with the error dialog text).
• Added missing translation keys based on english.json.

This change only affects the Japanese language JSON file and does not touch any Python logic. Thank you!

[sbillinge]

Thanks so much @NatsukiOgata this is great. Please could you also consider the following suggestions from AI (they were entries you didn't touch):

"close":

Current: "終了" (Means exit/terminate application)

Recommended: "閉じる" (Standard for closing a dialog, tab, or window without quitting the whole app).

"edit":

Current: "修正" (Means modify/correct an error)

Recommended: "編集" (Standard UI term for "Edit").

[NatsukiOgata]

Thank you for the review!

I agree with the suggestions. "閉じる" (Close) and "編集" (Edit) are indeed much more natural and standard UI terms in Japanese.

Along with those updates, I also adjusted the success_message ("閉じるボタンを押して終了します。") to ensure the message text matches the updated "閉じる" button label.

I have pushed the updated japanese.json to this PR. Please take a look when you have a chance!

[sbillinge]

Thanks so much. This is ready for merge. I just have to decide whether to merge it into master or the next release branch that is going out shortly. I will merge shortly when this is resolved. But nothing more required from you, and many thanks @NatsukiOgata

[NatsukiOgata]

Thank you so much! I'm glad I could contribute to Gooey.
Take your time with the merge. Looking forward to the next release!