Fixed managed settings keeping their plugin value after the configuration plugin was removed

app/MindWork AI Studio/Settings/ConfigMetaBase.cs

@@ -139,6 +139,29 @@ public abstract record ConfigMetaBase(string SettingName) : IConfig
         this.EditableDefaultByConfigPluginId = Guid.Empty;
     }
 
+    /// <summary>
+    /// Clears the editable-default state and hands the setting back to the user.
+    /// </summary>
+    /// <remarks>
+    /// Without a snapshot of the user's value, the current value stays as it is. That is the
+    /// difference to a locked setting: the user was allowed to change an editable default all
+    /// along, so its value is a plausible choice of theirs. Resetting it to the app's default would
+    /// take away something nobody asked us to remove.
+    /// </remarks>
+    /// <param name="keepCurrentValue">
+    /// True when the user has changed the value in the meantime. Their decision outlives the
+    /// configuration plugin, so the snapshot is dropped instead of applied.
+    /// </param>
+    public void ResetEditableDefaultConfiguration(bool keepCurrentValue)
+    {
+        this.ClearEditableDefaultConfiguration();
+
+        if (keepCurrentValue)
+            this.ClearUserValueSnapshot();
+        else
+            this.TryRestoreUserValueSnapshot();
+    }
+
     /// <summary>
     /// Removes the contribution of one configuration plugin without changing the current value.
     /// </summary>

app/MindWork AI Studio/Settings/ManagedConfiguration.Parsing.cs

@@ -1024,7 +1024,7 @@ public static partial class ManagedConfiguration
             case false when configMeta.ManagedMode is ManagedConfigurationMode.EDITABLE_DEFAULT
                             && TryGetEditableDefaultState(settingName, out var editableDefaultStateToRemove)
                             && editableDefaultStateToRemove.ConfigPluginId == configPluginId:
-                configMeta.ClearEditableDefaultConfiguration();
+                configMeta.ResetEditableDefaultConfiguration(HasUserChangedEditableDefault(configMeta, editableDefaultStateToRemove));
                 ClearEditableDefaultState(settingName);
                 break;
         }

app/MindWork AI Studio/Settings/ManagedConfiguration.cs

@@ -361,6 +361,19 @@ public static partial class ManagedConfiguration
                 configMeta.RemovePluginContribution(contributingConfigPluginId);
                 wasChanged = true;
             }
+
+            //
+            // Finally, drop any snapshot of the user's value which nobody claims anymore. Without
+            // this, a setting which stopped being managed outside of the paths above would keep its
+            // snapshot in the settings file forever. The persisted editable default counts as a
+            // claim as well: it survives a configuration plugin which is deployed but could not be
+            // loaded, and that plugin is still in charge:
+            //
+            if (configMeta.ManagedMode is null && !TryGetEditableDefaultState(configMeta.SettingName, out _) && configMeta.ClearUserValueSnapshot())
+            {
+                Log.LogInformation($"Dropping the snapshot of the user's value for the setting '{configMeta.SettingName}': no configuration plugin manages it anymore.");
+                wasChanged = true;
+            }
         }
 
         // Remove persisted states which belong to settings that do not exist anymore:
@@ -405,6 +418,13 @@ public static partial class ManagedConfiguration
             wasChanged = true;
         }
 
+        foreach (var settingName in configurationData.ManagedUserValueSnapshots.Keys.Where(x => !registeredSettingNames.Contains(x)).ToList())
+        {
+            Log.LogInformation($"Removing the snapshot of the user's value for the setting '{settingName}': this setting does not exist anymore.");
+            configurationData.ManagedUserValueSnapshots.Remove(settingName);
+            wasChanged = true;
+        }
+
         return wasChanged;
     }
 
@@ -447,7 +467,7 @@ public static partial class ManagedConfiguration
             if (configMeta.ManagedMode is not ManagedConfigurationMode.EDITABLE_DEFAULT)
                 return false;
 
-            configMeta.ClearEditableDefaultConfiguration();
+            configMeta.ResetEditableDefaultConfiguration(keepCurrentValue: false);
             return true;
         }
 
@@ -455,7 +475,17 @@ public static partial class ManagedConfiguration
             return false;
 
         Log.LogInformation($"Clearing the editable default of the setting '{configMeta.SettingName}': the configuration plugin '{editableDefaultState.ConfigPluginId}' is not available anymore.");
-        configMeta.ClearEditableDefaultConfiguration();
+        configMeta.ResetEditableDefaultConfiguration(HasUserChangedEditableDefault(configMeta, editableDefaultState));
         return ClearEditableDefaultState(configMeta.SettingName);
     }
+
+    /// <summary>
+    /// Checks whether the user has changed an editable default themselves.
+    /// </summary>
+    /// <remarks>
+    /// The user may change an editable default at any time. When the current value is not the one
+    /// the configuration plugin applied last, the user decided against that value, and their
+    /// decision outlives the plugin.
+    /// </remarks>
+    private static bool HasUserChangedEditableDefault(ConfigMetaBase configMeta, ManagedEditableDefaultState editableDefaultState) => !string.Equals(configMeta.SerializeCurrentValue(), editableDefaultState.LastAppliedValue, StringComparison.Ordinal);
 }