feat(ui): wählbares Listen-Icon und aufgeräumter Task-Detail-Header

Listen bekommen eine Icon-Spalte (Migration AddListIcon) und einen Icon-Picker
in den Listeneinstellungen; 34 kuratierte Geometrien aus der Icon-Bibliothek,
Fallback auf "Folder" bei unbekanntem Key.

Der Metadata-Footer im Task-Detail entfällt; created-at wandert in die
Header-Zeile neben das ID-Badge, der Close-Button (und CloseDetailsCommand)
fällt weg.

src/ClaudeDo.Ui/ViewModels/Modals/ListSettingsModalViewModel.cs

@@ -42,12 +42,34 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
     // lands; a non-zero exit keeps the task out of Done instead of silently reporting merged.
     [ObservableProperty] private string _verifyCommand = "";
     // Dropdown hidden entirely when no ticket-system base URL is configured (Settings → Files tab).
+    // Icon key into the UI icon library (IconKeyConverter -> "Icon.<key>" StreamGeometry).
+    [ObservableProperty] private string _icon = DefaultIcon;
     [ObservableProperty] private bool _ticketsAvailable;
     [ObservableProperty] private TicketProjectOption? _selectedTicketProject;
     public ObservableCollection<TicketProjectOption> TicketProjects { get; } = new();
 
     public ObservableCollection<string> CommitTypeOptions { get; } = new(CommitTypeRegistry.Types);
 
+    public const string DefaultIcon = "Folder";
+
+    // Curated subset of the Icon.* geometry library in IslandStyles.axaml — window chrome and
+    // pure stroke icons (PathIcon fills, so those render invisible) are deliberately left out.
+    // Grouped by theme so the picker grid reads in rows; every entry needs a matching
+    // "Icon.<key>" StreamGeometry or it renders as an empty slot.
+    public static readonly string[] IconOptions =
+    [
+        // general
+        "Folder", "Star", "Sun", "Calendar", "Clock", "Inbox", "Mail", "Text", "Search", "Grid",
+        // dev
+        "Code", "Terminal", "Database", "Server", "Chip", "Bolt", "Wand", "Flask", "Shield",
+        // status / flow
+        "Activity", "Eye", "Check", "Warning", "Chart", "Rocket", "Bulb", "Broom", "AgentSuggested", "Settings",
+        // things
+        "Box", "Truck", "MapPin", "Camera", "Image", "Barcode", "Skull",
+    ];
+
+    public ObservableCollection<string> Icons { get; } = new(IconOptions);
+
     // The shared agent-config editor (Model / MaxTurns / SystemPrompt / AgentFile),
     // scoped to this list (list → global inheritance).
     public AgentConfigEditorViewModel Agent { get; }
@@ -68,12 +90,16 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
         string defaultCommitType,
         bool isManual = false,
         bool findingsTracked = false,
+        string? icon = null,
         CancellationToken ct = default)
     {
         ListId = listId;
         Name = name;
         IsManual = isManual;
         FindingsTracked = findingsTracked;
+        // An unknown/legacy key would leave the picker with no selection and silently reset the
+        // icon on the next save — fall back to the default instead.
+        Icon = IconOptions.Contains(icon) ? icon! : DefaultIcon;
         WorkingDir = workingDir ?? "";
         DefaultCommitType = string.IsNullOrWhiteSpace(defaultCommitType) ? CommitTypeRegistry.DefaultType : defaultCommitType;
 
@@ -111,7 +137,8 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
             string.IsNullOrWhiteSpace(WorkingDir) ? null : WorkingDir,
             DefaultCommitType,
             IsManual,
-            FindingsTracked));
+            FindingsTracked,
+            Icon));
 
         // Tri-state: dropdown never shown (no base URL) -> null, leave the stored link alone.
         // Dropdown shown -> always an explicit value, 0 for "— none —" to actively clear it.