Improve Japanese translations and fix inconsistencies

[sigma7863]

Summary

This PR improves Japanese translations by fixing incorrect or missing translations, and updating wording for better clarity and consistency.

Changes

Translation fixes

• Fixed incorrect or placeholder translations (e.g. English text left in translations)
• Fixed typos and incorrect variable usage (e.g. {{revisions}} → {{count}})
• Ensured variables like {{name}} are properly reflected in translations

Wording improvements

• Replaced unnatural or overly literal expressions with more natural Japanese
• Improved clarity for UI instructions and messages
• Updated wording to better match the intent of the original text

Consistency improvements

• Unified tone (e.g. 「ある」→「あります」)
• Standardized terminology (e.g. 「パーミッション」→「権限」)
• Simplified or clarified phrasing where appropriate

Scope

• Multiple translation improvements across the UI
• No functional changes

Notes

I tried to keep translations natural and easy to understand for Japanese users while staying faithful to the original meaning.

If there are preferred wording or style guidelines, I’m happy to adjust accordingly.

[Copilot]

Pull request overview

This PR updates the Japanese locale file to improve translation completeness and consistency across the UI.

Changes:

• Replaces remaining English/placeholder strings with Japanese translations.
• Fixes wording/terminology for clarity and consistency (e.g., permissions wording, UI labels).
• Updates various strings to better reflect variables and intended meaning.

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[Copilot]

Placeholder name in the translation doesn't match the original: original uses {{ viewId }} but translation uses {{ viewID }} (different casing). This will prevent interpolation and may show the raw placeholder in the UI. Update the translation to use the exact same placeholder name as the original.

Suggested change

	translation=新しいベースビュー "{{ viewID }}" を追加できません。このIDを持つビューは既に存在します。
	translation=新しいベースビュー "{{ viewId }}" を追加できません。このIDを持つビューは既に存在します。