feat(manager): update managed Linux Spotify installations

[afonsojramos]

Summary

Manager now offers package updates for Spicetify-managed Linux Spotify installations. It shows the selected Linux feed's actual version and resumes the daemon's saved progress after Spotify restarts.

The update control requires a managed installation and a compatible package. Older daemons receive terminal guidance, and unavailable installation details do not hide a running or failed job. Native installations retain their existing update controls.

Publishes Manager 1.4.0 and stdlib 1.13.0. The managed updater requires the corresponding CLI beta.18 capability. Store advances to 1.7.8 so the already-merged recovery-link fix passes the repository's required version-bump gate.

Validation

Related: spicetify/cli#3953

• Live Manager-driven Spotify 1.2.84 to 1.2.96 update, successful restart, and persisted completion.
• Live failure recovery displayed the saved error after the prior working installation was restored.
• Manager and stdlib strict typechecks, formatting, dependency checks, and 857 module/repository tests passed locally.
• The unchanged submission-validator test hung in this environment and is left to the repository CI gate.

Summary by CodeRabbit

• New Features

  • Added an Updates section for daemon-managed Spotify installations.
  • Users can check for Spotify updates and apply available updates directly from the app.
  • Added stable and testing update channel support.
  • Update status now displays availability, progress, completion, and error messages.
  • When the manager is unavailable, users receive terminal instructions for updating Spotify.

• Bug Fixes

  • Improved update progress and failure messaging so status information remains accurate and preserves relevant error details.