Feature: audiobook/podcast skip controls

[andykelk]

Adds configurable skip controls for audiobooks and podcasts with user-selectable skip amounts of 10, 15, 30, or 60 seconds.

Features

• Forward and backward skip buttons appear only when playing audiobooks or podcasts
• Users can choose skip duration (10/15/30/60 seconds) in Settings > Audiobooks & Podcasts
• Rapid clicking accumulates skip time instead of jumping to the same position
• Works across mini player, fullscreen player, and browser media session controls
• Automatically detects audiobooks, podcasts, and podcast episodes

Implementation Details

• Skip buttons positioned between previous/next and play controls
• Generic fast-forward/rewind icons
• Shared SkipControlManager handles throttling logic similar to existing media session controls
• Browser media session uses configured amounts for keyboard/headphone controls
• Falls back to 10 seconds for music content to maintain existing behaviour

Test Plan

• Skip buttons appear only for audiobooks and podcasts
• Setting configurable in frontend settings under new "Audiobooks & Podcasts" category
• Skip amount changes are applied immediately without page refresh
• Rapid clicking accumulates skip time correctly
• Browser media session (keyboard/headphone controls) uses configured amounts
• No skip buttons shown for regular music content

Fixes https://github.com/orgs/music-assistant/discussions/3745

[marcelveldt]

Actually, server-side we also support skipping (for all media items, so also for tracks) - we simply never added it to the frontend. So if you prefer to use that, this would be the syntax:

command: "player_queues/skip"
parameters: {
  queue_id: string,
  seconds: number
}

seconds: number of seconds to skip in track. Use negative value to skip back.

[tsipinakis]

FYI I've patched the build errors: https://github.com/tsipinakis/mass-frontend/tree/nikos if you want to pull them

[OzGav]

@andykelk If you can fix the lint errors this can be progressed