feat: Implement layout persistence for card positions and rotation, loading from and saving to the database.

frontend/src/desktop/CardDragLogic.ts

@@ -55,4 +55,5 @@ export const handleDragEnd = (store: LayoutStore, selection: string[]) => {
             card.finishDrag();
         }
     });
+    store.saveLayout();
 };

frontend/src/desktop/DesktopWorkspace.tsx

@@ -54,6 +54,8 @@ export interface DesktopWorkspaceProps {
   onDocumentActivate?: (doc: DeskDocument, event?: unknown) => void;
   onSelectionChange?: (selectedIds: Identifier[]) => void;
   onDocumentTagDrop?: (docId: Identifier, tag: any) => void;
+  tenantId?: Identifier | null;
+  viewId?: string | null;
 }
 
 // Wrapper to handle hooks per card
@@ -84,6 +86,8 @@ const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
   onDocumentActivate,
   onSelectionChange,
   onDocumentTagDrop,
+  tenantId,
+  viewId,
 }) => {
   const containerRef = useRef<HTMLDivElement>(null);
 
@@ -99,6 +103,12 @@ const DesktopWorkspace: React.FC<DesktopWorkspaceProps> = ({
   const layoutStore = useMemo(() => new LayoutStore(), []);
   const layoutRef = useRef<Map<string, LayoutCard>>(new Map());
 
+  useEffect(() => {
+    if (tenantId && viewId) {
+      layoutStore.loadLayout(String(tenantId), viewId);
+    }
+  }, [layoutStore, tenantId, viewId]);
+
   // Selection Context
   const {
     selectedDocumentIds,

frontend/src/desktop/LayoutSystem.ts

@@ -1,4 +1,5 @@
 import { constrainDimensions } from './utils/layoutUtils';
+import { fetchLayoutRecords, upsertLayoutRecords } from './db';
 
 export interface LayoutCardState {
     id: string;
@@ -225,6 +226,10 @@ export class LayoutStore {
     items = new Map<string, LayoutCard>();
     zCounter = 100;
 
+    private savedLayouts = new Map<string, { x: number, y: number, rotation: number, z: number }>();
+    private tenantId: string | null = null;
+    private viewId: string | null = null;
+
     initialize(id: string, ref: HTMLElement | null, config: {
         width: number;
         height: number;
@@ -238,10 +243,27 @@ export class LayoutStore {
         );
 
         if (!card) {
-            // Apply defaults if not provided
-            const x = Math.random() * 500;
-            const y = Math.random() * 500;
-            const rotation = Math.random() * 10 - 5;
+            // Check for saved layout
+            const saved = this.savedLayouts.get(id);
+
+            let x, y, rotation, z;
+
+            if (saved) {
+                x = saved.x;
+                y = saved.y;
+                rotation = saved.rotation;
+                z = saved.z;
+                // Ensure zCounter is higher than any loaded z
+                if (z >= this.zCounter) {
+                    this.zCounter = z + 1;
+                }
+            } else {
+                // Apply defaults if not provided
+                x = Math.random() * 500;
+                y = Math.random() * 500;
+                rotation = Math.random() * 10 - 5;
+                z = this.zCounter++;
+            }
 
             card = new LayoutCard(id, this, {
                 x,
@@ -249,7 +271,7 @@ export class LayoutStore {
                 rotation,
                 width,
                 height,
-                z: this.zCounter++
+                z
             }, ref);
             this.items.set(id, card);
         } else {
@@ -319,4 +341,57 @@ export class LayoutStore {
     getSnapshot() {
         return Array.from(this.items.values()).map(card => card.toSnapshot());
     }
+
+    async loadLayout(tenantId: string, viewId: string) {
+        this.tenantId = tenantId;
+        this.viewId = viewId;
+
+        const records = await fetchLayoutRecords({ tenantId, viewId });
+
+        this.savedLayouts.clear();
+        let maxZ = this.zCounter;
+
+        for (const record of records) {
+            if (record.documentId && record.centerX !== undefined && record.centerY !== undefined) {
+                this.savedLayouts.set(record.documentId, {
+                    x: record.centerX,
+                    y: record.centerY,
+                    rotation: record.rotation || 0,
+                    z: record.zIndex || 0
+                });
+                if (record.zIndex && record.zIndex >= maxZ) {
+                    maxZ = record.zIndex + 1;
+                }
+            }
+        }
+
+        this.zCounter = maxZ;
+
+        // Apply to existing items if any (though usually this runs before items are created)
+        for (const [id, card] of this.items) {
+            const saved = this.savedLayouts.get(id);
+            if (saved) {
+                card.update(saved);
+            }
+        }
+    }
+
+    async saveLayout() {
+        if (!this.tenantId || !this.viewId) return;
+
+        const entries = Array.from(this.items.values()).map(card => ({
+            documentId: card.id,
+            centerX: card.x,
+            centerY: card.y,
+            rotation: card.rotation,
+            zIndex: card.z,
+            updatedAt: Date.now()
+        }));
+
+        await upsertLayoutRecords({
+            tenantId: this.tenantId,
+            viewId: this.viewId,
+            entries
+        });
+    }
 }

frontend/src/documents/panel/DocumentsPanel.tsx

@@ -839,7 +839,7 @@ const DocumentsPanelInner: React.FC<DocumentsPanelInnerProps> = ({
 
     switch (viewMode) {
       case 'desk':
-        return <DesktopWorkspace {...viewProps} />;
+        return <DesktopWorkspace {...viewProps} tenantId={currentTenantId} viewId={deskViewId} />;
       case 'grid':
         return <DocumentsGrid {...viewProps} gridIconSize={gridIconSize} />;
       case 'list':