feat: Integrate KanbanBoard component with drag-and-drop functionality using @hello-pangea/dnd

progress.txt

@@ -226,3 +226,26 @@
   - GanttChart is designed for reuse: the `defaultProjectId` prop on AddCheckpointDialog pre-selects the project and hides the dropdown (for per-project timeline in US-015)
   - `trpc.projects.listAll.useQuery(undefined, { enabled: showProjectSelect })` prevents unnecessary queries when project is already known
 ---
+
+## 2026-02-21 - US-014
+- What was implemented:
+  - Installed `@hello-pangea/dnd` for drag-and-drop support
+  - Created `KanbanBoard` component at `src/renderer/components/projects/KanbanBoard.tsx`
+  - `DragDropContext` wraps 3 `Droppable` columns: To Do (`todo`), In Progress (`in_progress`), Completed (`done`)
+  - Each task is a `Draggable` wrapping the shared `TaskRow` component (same UI as global Tasks view)
+  - Drag-and-drop between columns calls `tasks.update({ id, status })` via tRPC mutation
+  - Each column header shows: status label, `Badge` (variant=secondary) with task count, `Button` (variant=ghost, size=sm) with "+ Add"
+  - "+ Add" opens `NewTaskDialog` with `defaultProjectId` and `defaultStatus` pre-set to the column's status
+  - `EditTaskDialog` integrated for right-click context menu editing
+  - `tasks.delete` integrated for right-click context menu deletion
+  - Added "Tasks" section with `KanbanBoard` to `ProjectDetail.tsx` below the AI summary card
+  - Tasks with unknown status values fall back to the "To Do" column
+  - Drop zones highlight with `bg-muted/50` when dragging over
+- Files changed: `src/renderer/components/projects/KanbanBoard.tsx` (new), `src/renderer/components/projects/ProjectDetail.tsx`, `prd.json`, `progress.txt`, `package.json`, `package-lock.json`
+- **Learnings for future iterations:**
+  - `@hello-pangea/dnd` ships its own TypeScript declarations — no `@types/` package needed
+  - `TaskRow` component from the global Tasks view is fully reusable inside Kanban `Draggable` wrappers — its `ContextMenu` (Edit/Delete) still works correctly inside drag-and-drop contexts
+  - `NewTaskDialog` accepts `defaultStatus` prop which resets correctly on close via `resetAndClose()` — ideal for column-specific "+ Add" buttons
+  - When grouping tasks by status for Kanban columns, always handle unknown/null status values with a fallback to prevent tasks from disappearing
+  - `DragDropContext.onDragEnd` provides `draggableId` which maps directly to `task.id` — no need to look up the task object for status updates
+---