Show poster thumbnails in the detail panes

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/config/config_test.go

@@ -76,3 +76,24 @@ func TestLoadPermissionWarning(t *testing.T) {
 		t.Fatalf("unexpected warnings: %v", warnings)
 	}
 }
+
+func TestShowCovers(t *testing.T) {
+	base := `{"radarr":{"url":"http://r","apikey":"k"},"sonarr":{"url":"http://s","apikey":"k"},"sabnzbd":{"url":"http://a","apikey":"k"}`
+	for _, tc := range []struct {
+		ui   string
+		want bool
+	}{
+		{``, true},
+		{`,"ui":{}`, true},
+		{`,"ui":{"covers":true}`, true},
+		{`,"ui":{"covers":false}`, false},
+	} {
+		cfg, err := Parse([]byte(base + tc.ui + `}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got := cfg.UI.ShowCovers(); got != tc.want {
+			t.Errorf("%q: ShowCovers = %v, want %v", tc.ui, got, tc.want)
+		}
+	}
+}