Linthra 0.2.3

- Makes Linux playback recover more reliably from server/network drops and suspend/resume.
- Restores the Linux queue and position safely after an unexpected restart, without autoplay.
- Adds the first Audiobookshelf connection, authentication, and library foundation.
- Improves self-hosted server URLs, including IPv6 literals, and speeds up source re-syncs.
- Improves Linux defaults, System theme coverage, and player accessibility.
