Fix search input losing focus when hovering over dropdown items (Vibe Kanban) (#1966)

* Done! Here's a summary of the changes:

## Changes Made

### 1. `Dropdown.tsx` (lines 140-190)
- Added `preventFocusOnHover?: boolean` prop to `DropdownMenuItemProps` interface
- Added `onPointerMove` handler that calls `e.preventDefault()` when `preventFocusOnHover` is true, which stops Radix from stealing focus on hover

### 2. `SearchableDropdown.tsx` (line 110)
- Added `preventFocusOnHover` prop to `DropdownMenuItem`

### 3. `ProjectSelectorContainer.tsx` (lines 181, 208)
- Added `preventFocusOnHover` prop to both `DropdownMenuItem` components (the "Create new project" button and the virtualized project items)

The fix uses `e.preventDefault()` on `onPointerMove` to disable Radix's hover-to-focus behavior, as documented in [Radix UI Issue #2193](https://github.com/radix-ui/primitives/issues/2193). This preserves all other functionality (click, keyboard navigation, selection) while allowing the search input to retain focus when hovering over items.

* Done! I've added the `onPointerLeave` handler to `DropdownMenuItem` alongside the existing `onPointerMove` handler. Both now call `e.preventDefault()` when `preventFocusOnHover` is true.

**Summary of the fix:**
- Added `onPointerLeave` destructuring from props (line 161)
- Added `onPointerLeave` handler that calls `e.preventDefault()` when `preventFocusOnHover` is true (lines 187-194)

Per the [Radix UI Issue #2193](https://github.com/radix-ui/primitives/issues/2193), **both** `onPointerMove` and `onPointerLeave` need `preventDefault()` to fully disable hover-to-focus behavior.

frontend/src/components/ui-new/containers/ProjectSelectorContainer.tsx

@@ -180,6 +180,7 @@ export function ProjectSelectorContainer({
         <DropdownMenuItem
           onSelect={handleCreateClick}
           onMouseEnter={() => setHighlightedIndex(0)}
+          preventFocusOnHover
           icon={PlusIcon}
           className={cn(
             'text-accent',
@@ -208,6 +209,7 @@ export function ProjectSelectorContainer({
                 <DropdownMenuItem
                   onSelect={() => handleSelect(item)}
                   onMouseEnter={() => setHighlightedIndex(idx + 1)}
+                  preventFocusOnHover
                   className={cn(
                     isSelected && 'bg-secondary',
                     isHighlighted && 'bg-secondary'

frontend/src/components/ui-new/primitives/Dropdown.tsx

@@ -142,6 +142,8 @@ interface DropdownMenuItemProps
   icon?: Icon;
   badge?: string;
   variant?: 'default' | 'destructive';
+  /** When true, prevents hover from stealing focus (useful for searchable dropdowns) */
+  preventFocusOnHover?: boolean;
 }
 
 const DropdownMenuItem = React.forwardRef<
@@ -154,6 +156,9 @@ const DropdownMenuItem = React.forwardRef<
       icon: IconComponent,
       badge,
       variant = 'default',
+      preventFocusOnHover = false,
+      onPointerMove,
+      onPointerLeave,
       children,
       ...props
     },
@@ -171,6 +176,22 @@ const DropdownMenuItem = React.forwardRef<
         variant === 'destructive' && 'text-error',
         className
       )}
+      onPointerMove={
+        preventFocusOnHover
+          ? (e) => {
+              e.preventDefault();
+              onPointerMove?.(e);
+            }
+          : onPointerMove
+      }
+      onPointerLeave={
+        preventFocusOnHover
+          ? (e) => {
+              e.preventDefault();
+              onPointerLeave?.(e);
+            }
+          : onPointerLeave
+      }
       {...props}
     >
       {IconComponent && <IconComponent weight="bold" />}

frontend/src/components/ui-new/primitives/SearchableDropdown.tsx

@@ -108,6 +108,7 @@ export function SearchableDropdown<T>({
                 <DropdownMenuItem
                   onSelect={() => onSelect(item)}
                   onMouseEnter={() => onHighlightedIndexChange(idx)}
+                  preventFocusOnHover
                   badge={getItemBadge?.(item)}
                   className={cn(
                     isSelected && 'bg-secondary',