feat(HAI-004): add settings trigger to Header and wire into App

packages/dashboard/app/App.tsx

@@ -4,6 +4,7 @@ import { fetchConfig } from "./api";
 import { Header } from "./components/Header";
 import { Board } from "./components/Board";
 import { TaskDetailModal } from "./components/TaskDetailModal";
+import { SettingsModal } from "./components/SettingsModal";
 import { ToastContainer } from "./components/ToastContainer";
 import { useTasks } from "./hooks/useTasks";
 import { ToastProvider, useToast } from "./hooks/useToast";
@@ -11,6 +12,7 @@ import { ToastProvider, useToast } from "./hooks/useToast";
 function AppInner() {
   const [isCreating, setIsCreating] = useState(false);
   const [detailTask, setDetailTask] = useState<TaskDetail | null>(null);
+  const [settingsOpen, setSettingsOpen] = useState(false);
   const [maxConcurrent, setMaxConcurrent] = useState(2);
   const { tasks, createTask, moveTask, deleteTask, mergeTask } = useTasks();
 
@@ -41,7 +43,7 @@ function AppInner() {
 
   return (
     <>
-      <Header />
+      <Header onOpenSettings={() => setSettingsOpen(true)} />
       <Board
         tasks={tasks}
         maxConcurrent={maxConcurrent}
@@ -63,6 +65,9 @@ function AppInner() {
           addToast={addToast}
         />
       )}
+      {settingsOpen && (
+        <SettingsModal onClose={() => setSettingsOpen(false)} addToast={addToast} />
+      )}
       <ToastContainer toasts={toasts} onRemove={removeToast} />
     </>
   );

packages/dashboard/app/components/Header.tsx

@@ -1,10 +1,19 @@
-export function Header() {
+interface HeaderProps {
+  onOpenSettings?: () => void;
+}
+
+export function Header({ onOpenSettings }: HeaderProps) {
   return (
     <header className="header">
       <div className="header-left">
         <h1 className="logo">hai</h1>
         <span className="logo-sub">board</span>
       </div>
+      <div className="header-actions">
+        <button className="btn-icon" onClick={onOpenSettings} title="Settings">
+          ⚙
+        </button>
+      </div>
     </header>
   );
 }