1.15.1/extension system emby jellyfin

[oxyroid]

Summary

AI Agent Checklist

Before submitting this PR, confirm:

• I identified the task type.
• I read the root AGENTS.md.
• I read all relevant directory-level AGENTS.md files.
• I avoided unrelated refactors.
• I respected module dependency boundaries.
• I did not move low-level data access into UI.
• I did not introduce unnecessary dependencies.
• I ran the smallest relevant validation command.
• I documented any validation that could not be run.
• I listed risks or compatibility concerns.

Instructions Read

List the instruction files read for this change:

• AGENTS.md
• ...

Validation

Commands run:

./gradlew ...

Results:

...

Commands not run:

...

Reason:

...

Risk Notes

Mention any risk areas:

• API compatibility
• Database migration
• Playback behavior
• TV focus behavior
• Resource/i18n behavior
• Performance
• Binary size