better (but still broken) removal from playgrounds

src/nat/ArchiveController.kiss

@@ -328,4 +328,10 @@
     
     (defCommand SwitchPlayground [name (Text null)]
         (archive.changePlaygrounds ->:Void [:DynamicAccess<Dynamic> p] (dictSet p "default" name))
-        (when playgroundSystem (playgroundSystem.switchPlaygroundKey name))))
+        (when playgroundSystem (playgroundSystem.switchPlaygroundKey name)))
+        
+    (defCommand RemoveFromPlayground [entries (SelectedEntries 1 null)]
+        (for e entries
+            (when (hasComponent e Positions)
+                (withWritableComponents archive e [positions Positions]
+                    (positions.remove (dictGet archive.playgrounds "default")))) e)))

src/nat/systems/PlaygroundSystem.kiss

@@ -5,7 +5,8 @@
 
 (defNew [&prop :ArchiveUI ui
             :EntryChecker canProcess
-            &prop :PlaygroundEntryProcessor processor]
+            &prop :PlaygroundEntryProcessor processor
+            :EntryProcessor onRemoveEntry]
 
     (super
         ->[archive e]
@@ -21,7 +22,8 @@
                             (return null))))
                 (whenLet [pos (dictGet (readComponent e Positions) _playgroundKey)]
                     (processor archive e pos ui))
-            }))
+            })
+    (set this.onRemoveEntry onRemoveEntry))
 
 (method switchPlaygroundKey [key]
     (when _playgroundKey