feat(HAI-005): add auto-merge functionality for in-review tasks

- Add autoMerge boolean to Settings model with default false
- Add auto-merge toggle UI to the In Review column header
- Implement server-side auto-merge behavior in dashboard command
- Fix pre-existing build errors in types, executor, and dashboard server
- Update README with auto-merge documentation

packages/cli/src/commands/dashboard.ts

@@ -24,6 +24,20 @@ export async function runDashboard(port: number, opts: { engine?: boolean; open?
       onAgentTool: (name) => console.log(`[merger] tool: ${name}`),
     });
 
+  // Auto-merge: when a task lands in "in-review" and autoMerge is enabled, merge it
+  store.on("task:moved", async ({ task, to }) => {
+    if (to !== "in-review") return;
+    try {
+      const settings = await store.getSettings();
+      if (!settings.autoMerge) return;
+      console.log(`[auto-merge] Merging ${task.id}...`);
+      await onMerge(task.id);
+      console.log(`[auto-merge] ✓ ${task.id} merged`);
+    } catch (err: any) {
+      console.log(`[auto-merge] ✗ ${task.id}: ${err.message ?? err}`);
+    }
+  });
+
   // Start the web server with AI merge wired in
   const app = createServer(store, { onMerge });
 

packages/core/src/types.ts

@@ -47,6 +47,7 @@ export interface Settings {
   maxWorktrees: number;
   pollIntervalMs: number;
   groupOverlappingFiles: boolean;
+  autoMerge: boolean;
 }
 
 export const DEFAULT_SETTINGS: Settings = {
@@ -54,6 +55,7 @@ export const DEFAULT_SETTINGS: Settings = {
   maxWorktrees: 4,
   pollIntervalMs: 15000,
   groupOverlappingFiles: false,
+  autoMerge: false,
 };
 
 export interface BoardConfig {

packages/dashboard/app/App.tsx

@@ -1,6 +1,6 @@
 import { useState, useCallback, useEffect } from "react";
 import type { TaskDetail, TaskCreateInput, Task } from "@hai/core";
-import { fetchConfig } from "./api";
+import { fetchConfig, fetchSettings, updateSettings } from "./api";
 import { Header } from "./components/Header";
 import { Board } from "./components/Board";
 import { TaskDetailModal } from "./components/TaskDetailModal";
@@ -14,12 +14,16 @@ function AppInner() {
   const [detailTask, setDetailTask] = useState<TaskDetail | null>(null);
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [maxConcurrent, setMaxConcurrent] = useState(2);
+  const [autoMerge, setAutoMerge] = useState(false);
   const { tasks, createTask, moveTask, deleteTask, mergeTask } = useTasks();
 
   useEffect(() => {
     fetchConfig()
       .then((cfg) => setMaxConcurrent(cfg.maxConcurrent))
       .catch(() => {/* keep default */});
+    fetchSettings()
+      .then((s) => setAutoMerge(!!s.autoMerge))
+      .catch(() => {/* keep default */});
   }, []);
   const { toasts, addToast, removeToast } = useToast();
 
@@ -35,6 +39,16 @@ function AppInner() {
     [createTask],
   );
 
+  const handleToggleAutoMerge = useCallback(async () => {
+    const next = !autoMerge;
+    setAutoMerge(next);
+    try {
+      await updateSettings({ autoMerge: next });
+    } catch {
+      setAutoMerge(!next); // revert on failure
+    }
+  }, [autoMerge]);
+
   const handleDetailOpen = useCallback((task: TaskDetail) => {
     setDetailTask(task);
   }, []);
@@ -54,6 +68,8 @@ function AppInner() {
         onCancelCreate={handleCancelCreate}
         onCreateTask={handleCreateTask}
         onNewTask={handleCreateOpen}
+        autoMerge={autoMerge}
+        onToggleAutoMerge={handleToggleAutoMerge}
       />
       {detailTask && (
         <TaskDetailModal

packages/dashboard/app/components/Board.tsx

@@ -13,9 +13,11 @@ interface BoardProps {
   onCancelCreate: () => void;
   onCreateTask: (input: TaskCreateInput) => Promise<Task>;
   onNewTask: () => void;
+  autoMerge: boolean;
+  onToggleAutoMerge: () => void;
 }
 
-export function Board({ tasks, maxConcurrent, onMoveTask, onOpenDetail, addToast, isCreating, onCancelCreate, onCreateTask, onNewTask }: BoardProps) {
+export function Board({ tasks, maxConcurrent, onMoveTask, onOpenDetail, addToast, isCreating, onCancelCreate, onCreateTask, onNewTask, autoMerge, onToggleAutoMerge }: BoardProps) {
   return (
     <main className="board" id="board">
       {COLUMNS.map((col) => (
@@ -29,6 +31,7 @@ export function Board({ tasks, maxConcurrent, onMoveTask, onOpenDetail, addToast
           onOpenDetail={onOpenDetail}
           addToast={addToast}
           {...(col === "triage" ? { isCreating, onCancelCreate, onCreateTask, onNewTask } : {})}
+          {...(col === "in-review" ? { autoMerge, onToggleAutoMerge } : {})}
         />
       ))}
     </main>

packages/dashboard/app/components/Column.tsx

@@ -19,9 +19,11 @@ interface ColumnProps {
   onCancelCreate?: () => void;
   onCreateTask?: (input: TaskCreateInput) => Promise<Task>;
   onNewTask?: () => void;
+  autoMerge?: boolean;
+  onToggleAutoMerge?: () => void;
 }
 
-export function Column({ column, tasks, allTasks, maxConcurrent, onMoveTask, onOpenDetail, addToast, isCreating, onCancelCreate, onCreateTask, onNewTask }: ColumnProps) {
+export function Column({ column, tasks, allTasks, maxConcurrent, onMoveTask, onOpenDetail, addToast, isCreating, onCancelCreate, onCreateTask, onNewTask, autoMerge, onToggleAutoMerge }: ColumnProps) {
   const [dragOver, setDragOver] = useState(false);
 
   const handleDragOver = useCallback((e: React.DragEvent) => {
@@ -62,6 +64,17 @@ export function Column({ column, tasks, allTasks, maxConcurrent, onMoveTask, onO
         <div className={`column-dot dot-${column}`} />
         <h2>{COLUMN_LABELS[column]}</h2>
         <span className="column-count">{tasks.length}</span>
+        {column === "in-review" && onToggleAutoMerge && (
+          <label className="auto-merge-toggle" title={autoMerge ? "Auto-merge enabled" : "Auto-merge disabled"}>
+            <input
+              type="checkbox"
+              checked={!!autoMerge}
+              onChange={onToggleAutoMerge}
+            />
+            <span className="toggle-slider" />
+            <span className="toggle-label">Auto-merge</span>
+          </label>
+        )}
         {onNewTask && (
           <button className="btn btn-primary btn-sm" onClick={onNewTask}>
             + New Task

packages/dashboard/app/components/SettingsModal.tsx

@@ -9,7 +9,7 @@ interface SettingsModalProps {
 }
 
 export function SettingsModal({ onClose, addToast }: SettingsModalProps) {
-  const [form, setForm] = useState<Settings>({ maxConcurrent: 2, maxWorktrees: 4, pollIntervalMs: 15000, groupOverlappingFiles: false });
+  const [form, setForm] = useState<Settings>({ maxConcurrent: 2, maxWorktrees: 4, pollIntervalMs: 15000, groupOverlappingFiles: false, autoMerge: false });
   const [loading, setLoading] = useState(true);
 
   useEffect(() => {

packages/dashboard/app/styles.css

@@ -719,3 +719,53 @@ html, body {
   border-radius: var(--radius);
   margin: 4px;
 }
+
+/* Auto-merge toggle */
+.auto-merge-toggle {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  cursor: pointer;
+  user-select: none;
+  margin-left: auto;
+}
+
+.auto-merge-toggle input {
+  display: none;
+}
+
+.toggle-slider {
+  position: relative;
+  width: 28px;
+  height: 16px;
+  background: var(--border);
+  border-radius: 8px;
+  transition: background 0.2s;
+  flex-shrink: 0;
+}
+
+.toggle-slider::after {
+  content: "";
+  position: absolute;
+  top: 2px;
+  left: 2px;
+  width: 12px;
+  height: 12px;
+  background: var(--card);
+  border-radius: 50%;
+  transition: transform 0.2s;
+}
+
+.auto-merge-toggle input:checked + .toggle-slider {
+  background: var(--in-review);
+}
+
+.auto-merge-toggle input:checked + .toggle-slider::after {
+  transform: translateX(12px);
+}
+
+.toggle-label {
+  font-size: 11px;
+  color: var(--text-muted);
+  white-space: nowrap;
+}

packages/dashboard/src/server.ts

@@ -16,7 +16,7 @@ export interface ServerOptions {
   maxConcurrent?: number;
 }
 
-export function createServer(store: TaskStore, options?: ServerOptions) {
+export function createServer(store: TaskStore, options?: ServerOptions): ReturnType<typeof express> {
   const app = express();
   app.use(express.json());
 

packages/engine/src/executor.ts

@@ -226,7 +226,7 @@ export class TaskExecutor {
         ),
       }),
       execute: async (_toolCallId, params) => {
-        const { step, type: reviewType, step_name, baseline } = params;
+        const { step, type: reviewType, step_name, baseline } = params as { step: number; type: "plan" | "code"; step_name: string; baseline?: string };
 
         console.log(
           `[reviewer] ${taskId}: ${reviewType} review for Step ${step} (${step_name})`,