feat: Add initial random rotation for cards, introduce a PointerTrackingContext for pointer management, and include a design document for spatial workspace architecture.

frontend/src/desktop/DesktopWorkspace.tsx

@@ -16,6 +16,7 @@ import '../styles/workspace/workspace-items.css';
 import '../styles/workspace/workspace-cards.css';
 import { useWorkspaceSelectionContext } from '../app/WorkspaceSelectionContext';
 import { createDocumentEntryKey } from '../app/entryKey';
+import { PointerTrackingProvider, usePointerTracking } from './PointerTrackingContext';
 import type { Identifier } from '../types/identifiers';
 import type { DocumentsListEntry, Document } from '../types/documents';
 
@@ -77,9 +78,10 @@ const DesktopDocumentContainer: React.FC<React.ComponentProps<typeof DesktopDocu
     />
   );
 });
+
 DesktopDocumentContainer.displayName = 'DesktopDocumentContainer';
 
-const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
+const DesktopWorkspaceContent: React.FC<DesktopWorkspaceProps> = ({
   entries,
   ensureAssetUrl,
   getDocumentAsset,
@@ -89,6 +91,7 @@ const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
   tenantId,
   viewId,
 }) => {
+  const { addPointer, removePointer } = usePointerTracking();
   const containerRef = useRef<HTMLDivElement>(null);
   const [isLayoutReady, setIsLayoutReady] = useState(false);
 
@@ -219,10 +222,26 @@ const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
           onKeyDown={handleShellKeyDown}
           onPointerDown={(e) => {
             if (e.target === e.currentTarget) {
+              // Register background pointer
+              addPointer(e.pointerId);
+              (e.target as Element).setPointerCapture(e.pointerId);
+
               onClearSelection();
               focusShell();
             }
           }}
+          onPointerUp={(e) => {
+            if (e.target === e.currentTarget) {
+              removePointer(e.pointerId);
+              (e.target as Element).releasePointerCapture(e.pointerId);
+            }
+          }}
+          onPointerCancel={(e) => {
+            if (e.target === e.currentTarget) {
+              removePointer(e.pointerId);
+              (e.target as Element).releasePointerCapture(e.pointerId);
+            }
+          }}
         >
           {isLayoutReady && items.map((doc, index) => {
             const docId = doc.id ? String(doc.id) : `temp-${index}`;
@@ -295,4 +314,12 @@ const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
   );
 };
 
+const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = (props) => {
+  return (
+    <PointerTrackingProvider>
+      <DesktopWorkspaceContent {...props} />
+    </PointerTrackingProvider>
+  );
+};
+
 export default DesktopWorkspace;