Matugen: show toast & log on error

Assets/Translations/de.json

@@ -1750,6 +1750,10 @@
       "disabled": "Hintergrundbild-Farben deaktiviert",
       "not-installed": "Matugen nicht installiert - erforderlich für Hintergrundbild-Farbextraktion"
     },
+    "matugen": {
+      "failed": "Matugen-Verarbeitung fehlgeschlagen",
+      "failed-general": "Matugen ist beim Verarbeiten der Vorlagen auf einen Fehler gestoßen"
+    },
     "recording": {
       "stopping": "Aufnahme wird gestoppt…",
       "started": "Aufnahme gestartet",

Assets/Translations/en.json

@@ -1710,6 +1710,10 @@
       "disabled": "Wallpaper colors disabled",
       "not-installed": "Matugen not installed - required for wallpaper color extraction"
     },
+    "matugen": {
+      "failed": "Matugen processing failed",
+      "failed-general": "Matugen encountered an error while processing templates"
+    },
     "recording": {
       "stopping": "Stopping recording…",
       "started": "Recording started",

Assets/Translations/es.json

@@ -1710,6 +1710,10 @@
       "disabled": "Colores del fondo de pantalla desactivados",
       "not-installed": "Matugen no instalado - requerido para extraer colores del fondo de pantalla"
     },
+    "matugen": {
+      "failed": "Error en el procesamiento de Matugen",
+      "failed-general": "Matugen encontró un error al procesar las plantillas"
+    },
     "recording": {
       "stopping": "Deteniendo grabación...",
       "started": "Grabación iniciada",

Assets/Translations/fr.json

@@ -1710,6 +1710,10 @@
       "disabled": "Couleurs du fond d'écran désactivées",
       "not-installed": "Matugen non installé - requis pour l'extraction des couleurs du fond d'écran"
     },
+    "matugen": {
+      "failed": "Échec du traitement Matugen",
+      "failed-general": "Matugen a rencontré une erreur lors du traitement des modèles"
+    },
     "recording": {
       "stopping": "Arrêt de l'enregistrement...",
       "started": "Enregistrement démarré",

Assets/Translations/pt.json

@@ -1710,6 +1710,10 @@
       "disabled": "Cores do papel de parede desativadas",
       "not-installed": "Matugen não instalado - necessário para extração de cores do papel de parede"
     },
+    "matugen": {
+      "failed": "Falha no processamento do Matugen",
+      "failed-general": "Matugen encontrou um erro ao processar os modelos"
+    },
     "recording": {
       "stopping": "Parando gravação…",
       "started": "Gravação iniciada",

Assets/Translations/zh-CN.json

@@ -1710,6 +1710,10 @@
       "disabled": "壁纸颜色已禁用",
       "not-installed": "Matugen 未安装 - 壁纸颜色提取所需"
     },
+    "matugen": {
+      "failed": "Matugen 处理失败",
+      "failed-general": "Matugen 在处理模板时遇到错误"
+    },
     "recording": {
       "stopping": "正在停止录制…",
       "started": "录制已开始",

Services/AppThemeService.qml

@@ -454,6 +454,30 @@ Singleton {
     id: generateProcess
     workingDirectory: Quickshell.shellDir
     running: false
+    
+    onExited: function (exitCode) {
+      if (exitCode !== 0) {
+        // Capture error output from stderr first, then stdout, or use fallback message
+        const errorMsg = (stderr.text && stderr.text.trim() !== "") 
+          ? stderr.text.trim() 
+          : ((stdout.text && stdout.text.trim() !== "") 
+              ? stdout.text.trim() 
+              : I18n.tr("toast.matugen.failed-general"))
+        Logger.e("AppThemeService", "Matugen process failed with exit code:", exitCode)
+        if (stderr.text && stderr.text.trim() !== "") {
+          Logger.e("AppThemeService", "Matugen stderr:", stderr.text)
+        }
+        if (stdout.text && stdout.text.trim() !== "") {
+          Logger.e("AppThemeService", "Matugen stdout:", stdout.text)
+        }
+        ToastService.showError(
+          I18n.tr("toast.matugen.failed"),
+          errorMsg,
+          6000
+        )
+      }
+    }
+    
     stdout: StdioCollector {
       onStreamFinished: {
         if (this.text) {