Prepare Community Apps metadata and public installation documentation

[borg-codex-bot]

Parent: #22
Related umbrellas: #11, #27

Goal

Prepare Community Apps listing metadata and bilingual public installation documentation only after the publication gates are satisfied.

Blockers

• Localize in-app help and reload it on language changes #54: German and English in-app help completed.
• Rewrite the bilingual handbook after the UI redesign #53: German and English handbook and public documentation entry points completed.
• Define manual maintenance tests for fresh-system validation #21: Fresh-install and update checklist passed for the exact release candidate.
• Add German and English localization #11: Final localization release built and validated through the test channel.
• Introduce a unified professional UI design #27 through Validate and release the complete unified UI redesign #35: The complete UI redesign, shared foundation, page redesigns, and final redesign validation/release are completed.
• Explicit maintainer approval for Community Apps publication.

Scope

• Add Community Apps template and listing metadata.
• Add German and English installation and update guidance.
• Add stable installation, project, support, and documentation links only after explicit approval.
• Verify version, manifest, package URL, and checksum consistency.
• Ensure listing screenshots and descriptions match the final redesigned UI.

Acceptance criteria

• All blockers are documented as passed.
• Community Apps metadata is valid and contains no test-channel references.
• German and English installation guidance is equivalent.
• Public URLs target the approved stable release only.
• Listing text and screenshots match the completed redesign.
• No installation URL is published before explicit maintainer approval.

Release

This issue is intentionally deferred until localization, documentation, fresh-system validation, and the complete UI redesign are finished.