feat: add complete audiobook support

feat: add complete audiobook support

Adds comprehensive audiobook functionality to the Plex client including:

- Audiobook library browsing and detail screens
- Full-featured audiobook player with chapter navigation
- Author browsing and filtering
- Audiobook-specific UI widgets and controls
- Playback state management and seeking
- Integration with existing library navigation

This feature provides feature parity with video/music playback for
audiobook content types in Plex libraries.

Author: 8bitgentleman

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -6,9 +6,4 @@
           android:drawable="@drawable/ic_launcher_foreground"
           android:inset="16%" />
   </foreground>
-  <monochrome>
-      <inset
-          android:drawable="@drawable/ic_launcher_monochrome"
-          android:inset="16%" />
-  </monochrome>
 </adaptive-icon>

lib/constants/plex_constants.dart

@@ -0,0 +1,35 @@
+/// Constants for Plex API and player configuration
+class PlexConstants {
+  // Plex API Type Parameters
+  /// Type parameter for albums (used for audiobooks - shows books instead of artists)
+  static const int plexTypeAlbum = 9;
+
+  /// Type parameter for artists
+  static const int plexTypeArtist = 8;
+
+  /// Type parameter for tracks (chapters)
+  static const int plexTypeTrack = 10;
+
+  // Player Configuration
+  /// Maximum attempts to wait for player initialization
+  static const int maxPlayerInitAttempts = 100;
+
+  /// Interval between player initialization checks
+  static const Duration playerInitCheckInterval = Duration(milliseconds: 100);
+
+  /// Delay to ensure player is fully ready before seeking
+  static const Duration playerReadyDelay = Duration(milliseconds: 500);
+
+  /// Delay to verify seek operation completed
+  static const Duration seekVerificationDelay = Duration(milliseconds: 200);
+
+  // Progress Tracking
+  /// Interval for sending progress updates to Plex server
+  static const Duration progressUpdateInterval = Duration(seconds: 10);
+
+  // UI Behavior
+  /// Duration before hiding player controls automatically
+  static const Duration controlsHideDelay = Duration(seconds: 5);
+
+  PlexConstants._(); // Private constructor to prevent instantiation
+}

lib/models/plex_library.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/material.dart';
 import 'package:json_annotation/json_annotation.dart';
 
 part 'plex_library.g.dart';
@@ -30,4 +31,49 @@ class PlexLibrary {
       _$PlexLibraryFromJson(json);
 
   Map<String, dynamic> toJson() => _$PlexLibraryToJson(this);
+
+  /// Determines if this library is an audiobook library.
+  ///
+  /// Audiobooks in Plex are stored as music libraries (type: "artist") but use
+  /// specific metadata agents like audnexus, audiobooks, or audiobookshelf.
+  ///
+  /// Returns true if:
+  /// - The library type is "artist" AND
+  /// - The agent contains "audnexus", "audiobook", or "audiobookshelf" (case-insensitive)
+  ///
+  /// Returns false if:
+  /// - The library type is not "artist"
+  /// - The agent is null
+  /// - The agent doesn't contain any audiobook-specific patterns
+  bool get isAudiobookLibrary {
+    if (type.toLowerCase() != 'artist') return false;
+
+    final agentLower = agent?.toLowerCase() ?? '';
+    return agentLower.contains('audnexus') ||
+        agentLower.contains('audiobook') ||
+        agentLower.contains('audiobookshelf');
+  }
+
+  /// Returns the appropriate icon for this library type.
+  ///
+  /// Uses Icons.headphones for audiobook libraries, and type-specific icons
+  /// for other library types.
+  IconData get libraryIcon {
+    if (isAudiobookLibrary) {
+      return Icons.headphones;
+    }
+
+    switch (type.toLowerCase()) {
+      case 'movie':
+        return Icons.movie;
+      case 'show':
+        return Icons.tv;
+      case 'artist':
+        return Icons.music_note;
+      case 'photo':
+        return Icons.photo;
+      default:
+        return Icons.folder;
+    }
+  }
 }