Frontend/i18n: Better app store badge string keys

[tristanlabelle]

It's important to provide context on the string keys because in this case the translation shouldn't be what translators come up with from the English string, but rather Google's official translations for those.

Added an explanatory string in weblate.

Filed #8670 to follow up on supporting localized badges.

Testing

N/A

Web frontend checklist

• There are no console warnings when running the app
• Added tests where relevant
• Clicked around my changes running locally and it works
• Checked Desktop, Mobile and Tablet screen sizes

For maintainers

• Maintainers can push commits to my branch
• Maintainers can merge this PR for me

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Project	Deployment	Actions	Updated (UTC)
couchers	Ready	Preview	May 18, 2026 6:53am

[github-actions]

📝 Release Notes

This PR does not need to be included in release notes.

Reason: This PR only renames translation keys and adds translator context for app store badge accessibility text. It does not introduce a visible user-facing feature, significant UX improvement, or important technical infrastructure change that end users would notice.

🤖 Bot Debug Information

Model: couchers.openai.gpt-5.4
Decision: exclude
Reasoning: This PR only renames translation keys and adds translator context for app store badge accessibility text. It does not introduce a visible user-facing feature, significant UX improvement, or important technical infrastructure change that end users would notice.