core: improve how DMS handles multiple-sessions under the same user

quickshell/Common/Theme.qml

@@ -104,6 +104,8 @@ Singleton {
     signal matugenCompleted(string mode, string result)
     property var matugenColors: ({})
     property var _pendingGenerateParams: null
+    property int _colorsRetryCount: 0
+    property double _lastGenerateMs: 0
 
     property bool themeModeAutomationActive: false
     property bool dmsServiceWasDisconnected: true
@@ -1771,6 +1773,7 @@ Singleton {
         if (!matugenAvailable || isGreeterMode)
             return;
 
+        _lastGenerateMs = Date.now();
         _pendingGenerateParams = true;
         _themeGenerateDebounce.restart();
     }
@@ -2217,6 +2220,7 @@ Singleton {
         }
 
         onLoaded: {
+            _colorsRetryCount = 0;
             if (currentTheme === dynamic)
                 colorsFileLoadFailed = false;
             parseAndLoadColors();
@@ -2227,14 +2231,28 @@ Singleton {
         }
 
         onLoadFailed: function (error) {
-            if (currentTheme === dynamic) {
-                log.warn("Dynamic colors file load failed, marking for regeneration");
-                colorsFileLoadFailed = true;
-                const isGreeterMode = (typeof SessionData !== "undefined" && SessionData.isGreeterMode);
-                if (!isGreeterMode && matugenAvailable && rawWallpaperPath) {
-                    log.debug("Matugen available, triggering immediate regeneration");
-                    generateSystemThemesFromCurrentTheme();
-                }
+            if (currentTheme !== dynamic)
+                return;
+
+            if (SessionData.isGreeterMode)
+                return;
+
+            if (workerRunning) {
+                colorsReloadRetry.restart();
+                return;
+            }
+
+            if (_colorsRetryCount < 3) {
+                _colorsRetryCount++;
+                colorsReloadRetry.restart();
+                return;
+            }
+
+            colorsFileLoadFailed = true;
+            const stale = Date.now() - _lastGenerateMs > 5000;
+            if (matugenAvailable && rawWallpaperPath && stale) {
+                log.debug("Dynamic colors unrecoverable, regenerating");
+                generateSystemThemesFromCurrentTheme();
             }
         }
 
@@ -2243,6 +2261,13 @@ Singleton {
         }
     }
 
+    Timer {
+        id: colorsReloadRetry
+        interval: 150
+        repeat: false
+        onTriggered: dynamicColorsFileView.reload()
+    }
+
     IpcHandler {
         target: "theme"