feat(ui): session-skills empty-state + neutral subtask terminology

Show an explanatory empty-state under the install row when no skills are
installed. Rename the unified-parent status/labels from "Improvements" to
neutral "Subtasks" (waitingForChildren, agentStatus.children,
childOutcomesLabel) since WaitingForChildren now covers planning too.

src/ClaudeDo.Localization/locales/de.json

@@ -108,7 +108,8 @@
       "installButton": "Installieren",
       "installedSection": "INSTALLIERT",
       "updateButton": "Aktualisieren",
-      "removeButton": "Entfernen"
+      "removeButton": "Entfernen",
+      "emptyState": "Keine Skills installiert — oben eine GitHub-URL einfügen, um einen hinzuzufügen."
     }
   },
   "tasks": {
@@ -188,7 +189,7 @@
     "mergeTargetLabel": "Merge-Ziel",
     "reviewCombinedDiff": "Kombiniertes Diff prüfen",
     "mergeAllSubtasks": "Alle Teilaufgaben mergen",
-    "childOutcomesLabel": "VERBESSERUNGEN",
+    "childOutcomesLabel": "TEILAUFGABEN",
     "stepsLabel": "SCHRITTE",
     "addStepPlaceholder": "Schritt hinzufügen...",
     "detailsLabel": "DETAILS",
@@ -500,8 +501,8 @@
   "vm": {
     "connection": { "online": "Online", "connecting": "Verbinden…", "offline": "Offline" },
     "shell": { "restartingWorker": "Worker wird neu gestartet…" },
-    "agentStatus": { "idle": "Leerlauf", "queued": "In Warteschlange", "running": "Läuft", "review": "Prüfung", "children": "Wartet auf Verbesserungen", "done": "Fertig", "failed": "Fehlgeschlagen", "cancelled": "Abgebrochen" },
+    "agentStatus": { "idle": "Leerlauf", "queued": "In Warteschlange", "running": "Läuft", "review": "Prüfung", "children": "Wartet auf Teilaufgaben", "done": "Fertig", "failed": "Fehlgeschlagen", "cancelled": "Abgebrochen" },
-    "taskStatus": { "idle": "Leerlauf", "queued": "In Warteschlange", "running": "Läuft", "waitingForReview": "Wartet auf Prüfung", "waitingForChildren": "Wartet auf Verbesserungen", "done": "Fertig", "failed": "Fehlgeschlagen", "cancelled": "Abgebrochen", "parked": "Geparkt" },
+    "taskStatus": { "idle": "Leerlauf", "queued": "In Warteschlange", "running": "Läuft", "waitingForReview": "Wartet auf Prüfung", "waitingForChildren": "Wartet auf Teilaufgaben", "done": "Fertig", "failed": "Fehlgeschlagen", "cancelled": "Abgebrochen", "parked": "Geparkt" },
     "planningBadge": { "active": "PLANUNG", "finalized": "GEPLANT" },
     "taskRow": { "createdPrefix": "Erstellt {0}", "stepsText": "{0}/{1} Schritte" },
     "tasksIsland": { "completedHeader": "ABGESCHLOSSEN", "completedHeaderCount": "ABGESCHLOSSEN · {0}", "planningOpenFailed": "Planungssitzung konnte nicht geöffnet werden: {0}", "pickUpInTerminalFailed": "Im Terminal fortsetzen fehlgeschlagen: {0}", "approveFailed": "Genehmigen & Mergen fehlgeschlagen: {0}" },

src/ClaudeDo.Localization/locales/en.json

@@ -108,7 +108,8 @@
       "installButton": "Install",
       "installedSection": "INSTALLED",
       "updateButton": "Update",
-      "removeButton": "Remove"
+      "removeButton": "Remove",
+      "emptyState": "No skills installed — paste a GitHub URL above to add one."
     }
   },
   "tasks": {
@@ -188,7 +189,7 @@
     "mergeTargetLabel": "Merge target",
     "reviewCombinedDiff": "Review combined diff",
     "mergeAllSubtasks": "Merge all subtasks",
-    "childOutcomesLabel": "IMPROVEMENTS",
+    "childOutcomesLabel": "SUBTASKS",
     "stepsLabel": "STEPS",
     "addStepPlaceholder": "Add a step...",
     "detailsLabel": "DETAILS",
@@ -500,8 +501,8 @@
   "vm": {
     "connection": { "online": "Online", "connecting": "Connecting…", "offline": "Offline" },
     "shell": { "restartingWorker": "Restarting worker…" },
-    "agentStatus": { "idle": "Idle", "queued": "Queued", "running": "Running", "review": "Review", "children": "Waiting for Improvements", "done": "Done", "failed": "Failed", "cancelled": "Cancelled" },
+    "agentStatus": { "idle": "Idle", "queued": "Queued", "running": "Running", "review": "Review", "children": "Waiting for Subtasks", "done": "Done", "failed": "Failed", "cancelled": "Cancelled" },
-    "taskStatus": { "idle": "Idle", "queued": "Queued", "running": "Running", "waitingForReview": "Waiting for Review", "waitingForChildren": "Waiting for Improvements", "done": "Done", "failed": "Failed", "cancelled": "Cancelled", "parked": "Parked" },
+    "taskStatus": { "idle": "Idle", "queued": "Queued", "running": "Running", "waitingForReview": "Waiting for Review", "waitingForChildren": "Waiting for Subtasks", "done": "Done", "failed": "Failed", "cancelled": "Cancelled", "parked": "Parked" },
     "planningBadge": { "active": "PLANNING", "finalized": "PLANNED" },
     "taskRow": { "createdPrefix": "Created {0}", "stepsText": "{0}/{1} steps" },
     "tasksIsland": { "completedHeader": "COMPLETED", "completedHeaderCount": "COMPLETED · {0}", "planningOpenFailed": "Couldn't open planning session: {0}", "pickUpInTerminalFailed": "Pick up in terminal failed: {0}", "approveFailed": "Approve & merge failed: {0}" },

src/ClaudeDo.Ui/ViewModels/Modals/Settings/SessionSkillsSettingsTabViewModel.cs

@@ -13,6 +13,7 @@ public sealed partial class SessionSkillsSettingsTabViewModel : ViewModelBase
     [ObservableProperty] private string _installUrl = "";
     [ObservableProperty] private string _statusMessage = "";
     [ObservableProperty] private bool _isBusy;
+    [ObservableProperty] private bool _isEmpty = true;
 
     public ObservableCollection<SessionSkillDto> Skills { get; } = new();
 
@@ -26,6 +27,7 @@ public sealed partial class SessionSkillsSettingsTabViewModel : ViewModelBase
             var skills = await _worker.GetSessionSkillsAsync();
             Skills.Clear();
             foreach (var s in skills) Skills.Add(s);
+            IsEmpty = Skills.Count == 0;
         }
         finally { IsBusy = false; }
     }

src/ClaudeDo.Ui/Views/Modals/SettingsModalView.axaml

@@ -413,6 +413,9 @@
                     </DataTemplate>
                   </ItemsControl.ItemTemplate>
                 </ItemsControl>
+                <TextBlock Classes="meta" Opacity="0.6" TextWrapping="Wrap"
+                           Text="{loc:Tr settings.skills.emptyState}"
+                           IsVisible="{Binding SessionSkills.IsEmpty}"/>
               </StackPanel>
 
               <TextBlock Classes="meta" Text="{Binding SessionSkills.StatusMessage}"