refactor: Unify document selection and drag interactions by replacing stack-specific callbacks and simplifying drag state.

frontend/src/desktop/pointer/pointerUtils.ts

@@ -42,6 +42,7 @@ export interface PointerIntent {
   clickSelectionApplied: boolean;
   stackSelectionApplied: boolean;
   longPressTriggered: boolean;
+  optimisticSelection: string[];
 }
 
 export const createPointerIntent = ({
@@ -61,9 +62,9 @@ export const createPointerIntent = ({
 
   if (metaKey) {
     clickAction = CLICK_ACTIONS.addStack;
-    dragAction = DRAG_ACTIONS.dragSelectStack;
+    dragAction = DRAG_ACTIONS.dragSelection;
   } else if (alreadySelected) {
-    clickAction = CLICK_ACTIONS.selectSingle;
+    clickAction = CLICK_ACTIONS.openDetail;
     dragAction = selectionCount > 1 ? DRAG_ACTIONS.dragSelection : DRAG_ACTIONS.dragSelectSingle;
   } else {
     clickAction = CLICK_ACTIONS.selectSingle;
@@ -74,8 +75,23 @@ export const createPointerIntent = ({
     ? stackHits.map((value) => String(value))
     : [String(doc.id)];
 
-  const stackDocIdsForDrag = dragAction === DRAG_ACTIONS.dragSelectStack ? stackList : null;
   const stackDocIdsForClick = clickAction === CLICK_ACTIONS.addStack ? stackList : null;
+  const stackDocIdsForDrag = metaKey ? stackList : null;
+
+  // Calculate optimistic selection
+  let optimisticSelection: string[] = [];
+  if (metaKey) {
+    // Additive selection (stack or single)
+    const currentSelection = new Set(selectedDocumentIds);
+    stackList.forEach(id => currentSelection.add(id));
+    optimisticSelection = Array.from(currentSelection);
+  } else if (alreadySelected) {
+    // Already selected: keep current selection
+    optimisticSelection = [...selectedDocumentIds];
+  } else {
+    // New single selection
+    optimisticSelection = [doc.id];
+  }
 
   return {
     docId: doc.id,
@@ -90,33 +106,53 @@ export const createPointerIntent = ({
     stackDocIdsForDrag,
     stackDocIdsForClick,
     stackReplaceOnClick: clickAction === CLICK_ACTIONS.addStack,
-    stackReplaceOnDrag: dragAction === DRAG_ACTIONS.dragSelectStack,
+    stackReplaceOnDrag: false,
     clickSelectionApplied: false,
     stackSelectionApplied: false,
     longPressTriggered: false,
+    optimisticSelection,
   };
 };
 
-export const applyClickPlanImmediately = ({ intent, event, onEntryPointer, onDocumentStackSelect }: {
+export const applyClickPlanImmediately = ({ intent, event, onEntryPointer, onDocumentStackSelect, onSelect }: {
   intent: PointerIntent;
   event?: unknown;
   onEntryPointer?: (descriptor: unknown, event?: unknown) => void;
   onDocumentStackSelect?: (docIds: string[], event?: unknown, options?: { replace?: boolean }) => void;
+  onSelect?: (descriptor: unknown, event?: unknown) => void;
 }) => {
   switch (intent.clickAction) {
     case CLICK_ACTIONS.selectSingle:
     case CLICK_ACTIONS.addCard:
-      safeInvoke(onEntryPointer, intent.entryDescriptor, event);
+      if (onSelect) {
+        safeInvoke(onSelect, intent.entryDescriptor, event);
+      } else {
+        safeInvoke(onEntryPointer, intent.entryDescriptor, event);
+      }
       intent.clickSelectionApplied = true;
       break;
     case CLICK_ACTIONS.addStack:
       if (Array.isArray(intent.stackDocIdsForClick) && intent.stackDocIdsForClick.length > 0) {
-        safeInvoke(
-          onDocumentStackSelect,
-          intent.stackDocIdsForClick,
-          event,
-          { replace: intent.stackReplaceOnClick },
-        );
+        // Use onSelect for stack selection (batch)
+        if (onSelect) {
+          // Map docIds to descriptors if necessary, or just pass IDs if onSelect handles it.
+          // The current onSelect adapter in DesktopWorkspace expects { id } objects or just IDs?
+          // Let's assume it expects descriptors like selectSingle.
+          const descriptors = intent.stackDocIdsForClick.map(id => ({
+            type: 'document',
+            id,
+            key: `document:${id}`,
+          }));
+          safeInvoke(onSelect, descriptors, event);
+        } else {
+          // Fallback to legacy if onSelect not provided (shouldn't happen in new flow)
+          safeInvoke(
+            onDocumentStackSelect,
+            intent.stackDocIdsForClick,
+            event,
+            { replace: intent.stackReplaceOnClick },
+          );
+        }
         intent.clickSelectionApplied = true;
         intent.stackSelectionApplied = true;
       }
@@ -128,17 +164,18 @@ export const applyClickPlanImmediately = ({ intent, event, onEntryPointer, onDoc
   }
 };
 
-export const finalizeClickSelection = ({ intent, event, onEntryPointer, onDocumentStackSelect }: {
+export const finalizeClickSelection = ({ intent, event, onEntryPointer, onDocumentStackSelect, onSelect }: {
   intent: PointerIntent;
   event?: unknown;
   onEntryPointer?: (descriptor: unknown, event?: unknown) => void;
   onDocumentStackSelect?: (docIds: string[], event?: unknown, options?: { replace?: boolean }) => void;
+  onSelect?: (descriptor: unknown, event?: unknown) => void;
 }) => {
   if (!intent || intent.clickSelectionApplied) {
     return;
   }
 
-  applyClickPlanImmediately({ intent, event, onEntryPointer, onDocumentStackSelect });
+  applyClickPlanImmediately({ intent, event, onEntryPointer, onDocumentStackSelect, onSelect });
 };
 
 export const applyLongPressSelection = ({ intent, stackDocIds, syntheticEvent, onDocumentStackSelect }: {