fix: blurry cover images

lib/screens/discover_screen.dart

@@ -1375,12 +1375,13 @@ class _DiscoverScreenState extends State<DiscoverScreen>
                       builder: (context) {
                         final client = _getClientForItem(heroItem);
                         final mediaQuery = MediaQuery.of(context);
+                        final dpr = PlexImageHelper.effectiveDevicePixelRatio(context);
                         final imageUrl = PlexImageHelper.getOptimizedImageUrl(
                           client: client,
                           thumbPath: heroItem.art ?? heroItem.grandparentArt,
                           maxWidth: mediaQuery.size.width,
                           maxHeight: mediaQuery.size.height * 0.7,
-                          devicePixelRatio: mediaQuery.devicePixelRatio,
+                          devicePixelRatio: dpr,
                           imageType: ImageType.art,
                         );
 
@@ -1442,7 +1443,7 @@ class _DiscoverScreenState extends State<DiscoverScreen>
                         child: Builder(
                           builder: (context) {
                             final client = _getClientForItem(heroItem);
-                            final dpr = MediaQuery.of(context).devicePixelRatio;
+                            final dpr = PlexImageHelper.effectiveDevicePixelRatio(context);
                             final logoUrl = PlexImageHelper.getOptimizedImageUrl(
                               client: client,
                               thumbPath: heroItem.clearLogo,

lib/screens/media_detail_screen.dart

@@ -1283,12 +1283,13 @@ class _MediaDetailScreenState extends State<MediaDetailScreen> with WatchStateAw
                                   // Online - use network image
                                   final client = _getClientForMetadata(context);
                                   final mediaQuery = MediaQuery.of(context);
+                                  final dpr = PlexImageHelper.effectiveDevicePixelRatio(context);
                                   final imageUrl = PlexImageHelper.getOptimizedImageUrl(
                                     client: client,
                                     thumbPath: metadata.art,
                                     maxWidth: mediaQuery.size.width,
                                     maxHeight: mediaQuery.size.height * 0.6,
-                                    devicePixelRatio: mediaQuery.devicePixelRatio,
+                                    devicePixelRatio: dpr,
                                     imageType: ImageType.art,
                                   );
 
@@ -1366,7 +1367,7 @@ class _MediaDetailScreenState extends State<MediaDetailScreen> with WatchStateAw
 
                                         // Online - use network image
                                         final client = _getClientForMetadata(context);
-                                        final dpr = MediaQuery.of(context).devicePixelRatio;
+                                        final dpr = PlexImageHelper.effectiveDevicePixelRatio(context);
                                         final logoUrl = PlexImageHelper.getOptimizedImageUrl(
                                           client: client,
                                           thumbPath: metadata.clearLogo,

lib/utils/plex_image_helper.dart

@@ -1,4 +1,6 @@
 import 'dart:math';
+import 'dart:ui';
+import 'package:flutter/widgets.dart';
 import '../services/plex_client.dart';
 import 'plex_url_helper.dart';
 
@@ -32,6 +34,21 @@ class PlexImageHelper {
     );
   }
 
+  /// Computes an effective device pixel ratio that accounts for displays where
+  /// the platform-reported DPR doesn't reflect the true physical density
+  /// (common on Linux X11 with compositor scaling).
+  static double effectiveDevicePixelRatio(BuildContext context) {
+    final reportedDpr = MediaQuery.of(context).devicePixelRatio;
+    try {
+      final displayWidth = View.of(context).display.size.width;
+      // Scale quality with display resolution: 1920px = baseline (1.0x)
+      final displayBasedDpr = (displayWidth / 1920).clamp(1.0, 3.0);
+      return max(reportedDpr, displayBasedDpr);
+    } catch (_) {
+      return reportedDpr;
+    }
+  }
+
   /// Calculates optimal image dimensions based on image type and constraints
   static (int width, int height) calculateOptimalDimensions({
     required double maxWidth,
@@ -74,9 +91,9 @@ class PlexImageHelper {
         return roundDimensions(size, size);
 
       case ImageType.poster:
-        // For posters, maintain 2:3 aspect ratio
-        final calculatedWidth = min(targetWidth, targetHeight / (2 / 3));
-        final calculatedHeight = calculatedWidth * (2 / 3);
+        // For posters, maintain 2:3 aspect ratio (width:height)
+        final calculatedWidth = min(targetWidth, targetHeight * (2 / 3));
+        final calculatedHeight = calculatedWidth * (3 / 2);
         return roundDimensions(calculatedWidth, calculatedHeight);
     }
   }

lib/widgets/plex_optimized_image.dart

@@ -258,7 +258,7 @@ class PlexOptimizedImage extends StatelessWidget {
 
     return LayoutBuilder(
       builder: (context, constraints) {
-        final devicePixelRatio = MediaQuery.of(context).devicePixelRatio;
+        final devicePixelRatio = PlexImageHelper.effectiveDevicePixelRatio(context);
 
         // Calculate effective constraints with safe fallbacks
         final effectiveWidth = resolvedDimension(width, constraints.maxWidth, 300.0);