fix: Update German translation for push sharing message

[GoliathLabs]

Description

Apparently, this was auto translated. "Pressemitteilung" doesn't make sense here.

Related Issue

Type of Change

• 📦 Dependency & security updates
• 🔧 Bug fix (non-breaking change which fixes an issue)
• 🥂 Improvement (non-breaking change which improves an existing feature)
• 🚀 New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🔐 Security fix
• 📚 Examples / documentation / tutorials

Checklist

• I've written tests (if applicable) for all new methods and classes that I created. (rake test)
• I've added documentation as necessary so users can easily use and understand this feature/fix.

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Note

Low Risk
Single German gettext string correction with no runtime or security impact.

Overview
Fixes the German string on the push preview page (preview.html.erb) for "Copy the link or message below to share this push securely."

The previous translation used "Pressemitteilung" (press release), which is a bad auto-translation for Password Pusher’s push feature. It now uses "diesen Push", consistent with other German entries in the same locale file (e.g. push created / push ownership strings).

Only config/locales/gettext/de/app.po changes; no application logic.

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