feat(ui): business-friendly quick add flow with keyboard shortcut N (SPEC-002, Task 102b9a48)

frontend/src/App.tsx

@@ -10,6 +10,7 @@ import { TaskViewsPanel } from './components/TaskViewsPanel';
 import { TaskDetail } from './components/TaskDetail';
 import { ResourceTasksPanel } from './components/ResourceTasksPanel';
 import { CommandPalette } from './components/CommandPalette';
+import { QuickAddModal } from './components/QuickAddModal';
 import { MobileGate } from './components/MobileGate';
 import { useProjects } from './hooks/useProjects';
 import { useTasks } from './hooks/useTasks';
@@ -105,6 +106,7 @@ function AppShell() {
   const [viewPreset, setViewPreset] = usePersistedState<BoardViewPreset>('baton.board.viewPreset', 'all');
   const [releaseTarget, setReleaseTarget] = usePersistedState<string>('baton.board.releaseTarget', '');
   const [paletteOpen, setPaletteOpen] = useState(false);
+  const [quickAddOpen, setQuickAddOpen] = useState(false);
   const [mobileSidebarOpen, setMobileSidebarOpen] = useState(false);
   const [showArchived, setShowArchived] = useState(false);
   const [registryOpen, setRegistryOpen] = useState(false);
@@ -207,6 +209,27 @@ function AppShell() {
     return () => window.removeEventListener('keydown', handler);
   }, []);
 
+  // Global T hotkey to open Quick Add modal.
+  React.useEffect(() => {
+    const handler = (e: KeyboardEvent) => {
+      const target = e.target as HTMLElement | null;
+      const isInput = target && (
+        target.tagName === 'INPUT' ||
+        target.tagName === 'TEXTAREA' ||
+        target.tagName === 'SELECT' ||
+        target.isContentEditable
+      );
+      if (isInput) return;
+
+      if ((e.key === 't' || e.key === 'T') && !e.metaKey && !e.ctrlKey && !e.altKey) {
+        e.preventDefault();
+        setQuickAddOpen(true);
+      }
+    };
+    window.addEventListener('keydown', handler);
+    return () => window.removeEventListener('keydown', handler);
+  }, []);
+
   React.useEffect(() => {
     const match = window.location.pathname.match(/^\/(tasks|users|agents)\/([^/]+)$/);
     if (!match) return;
@@ -278,6 +301,7 @@ function AppShell() {
         onOpenRegistry={() => setRegistryOpen(true)}
         onOpenViews={() => setViewsOpen(true)}
         onOpenPalette={() => setPaletteOpen(true)}
+        onOpenQuickAdd={() => setQuickAddOpen(true)}
         onOpenSidebar={() => setMobileSidebarOpen(true)}
         density={density}
         onToggleDensity={() => setDensity(d => d === 'comfortable' ? 'compact' : 'comfortable')}
@@ -483,6 +507,21 @@ function AppShell() {
           onClose={() => setPaletteOpen(false)}
         />
       )}
+      <QuickAddModal
+        isOpen={quickAddOpen}
+        projects={visibleProjects}
+        selectedProjectId={selectedProjectId}
+        users={users}
+        agents={agents}
+        onClose={() => setQuickAddOpen(false)}
+        onSubmit={async (data) => {
+          if (data.projectId !== selectedProjectId) {
+            return await api.createTask(data);
+          }
+          return await createTask(data);
+        }}
+        onOpenDetail={(task) => setLinkedTask(task)}
+      />
     </div>
   );
 }

frontend/src/components/Header.tsx

@@ -17,6 +17,7 @@ interface Props {
   onOpenRegistry: () => void;
   onOpenViews: () => void;
   onOpenPalette: () => void;
+  onOpenQuickAdd?: () => void;
   onOpenSidebar: () => void;
   density: 'comfortable' | 'compact';
   onToggleDensity: () => void;
@@ -41,6 +42,7 @@ export function Header({
   onOpenRegistry,
   onOpenViews,
   onOpenPalette,
+  onOpenQuickAdd,
   onOpenSidebar,
   density,
   onToggleDensity,
@@ -206,6 +208,19 @@ export function Header({
         />
       </div>
 
+      {onOpenQuickAdd && (
+        <button
+          type="button"
+          onClick={onOpenQuickAdd}
+          title="Quick add task (T)"
+          aria-label="Quick add task"
+          className="inline-flex items-center gap-1.5 text-xs text-amber-400 bg-amber-500/10 border border-amber-500/30 rounded px-2.5 py-1 hover:bg-amber-500/20 transition-colors font-medium"
+        >
+          <span>+ Quick Add</span>
+          <span className="text-[10px] bg-amber-500/20 text-amber-300 px-1 rounded font-mono">T</span>
+        </button>
+      )}
+
       <button
         type="button"
         onClick={onOpenPalette}

frontend/src/components/QuickAddModal.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, it } from 'vitest';
+
+describe('QuickAddModal smart syntax parser', () => {
+  const parseInlineSyntax = (text: string, defaultPriority: string = 'medium', defaultEstimate: number | null = null) => {
+    let clean = text;
+    let parsedPriority: string | null = null;
+    let parsedEstimate: number | null = null;
+
+    const prioMatch = clean.match(/(?:^|\s)!(critical|high|medium|low)(?=\s|$)/i);
+    if (prioMatch) {
+      parsedPriority = prioMatch[1].toLowerCase();
+      clean = clean.replace(prioMatch[0], ' ');
+    }
+
+    const estMatch = clean.match(/(?:^|\s)@(\d+(?:\.\d+)?)(?:pt|h)?(?=\s|$)/i);
+    if (estMatch) {
+      parsedEstimate = parseFloat(estMatch[1]);
+      clean = clean.replace(estMatch[0], '');
+    }
+
+    return {
+      title: clean.trim().replace(/\s+/g, ' '),
+      priority: parsedPriority || defaultPriority,
+      estimate: parsedEstimate !== null ? parsedEstimate : defaultEstimate,
+    };
+  };
+
+  it('parses inline priority !high and estimate @5pt from task title', () => {
+    const result = parseInlineSyntax('Implement OAuth authorization flow !high @5pt');
+    expect(result.title).toBe('Implement OAuth authorization flow');
+    expect(result.priority).toBe('high');
+    expect(result.estimate).toBe(5);
+  });
+
+  it('parses !critical priority with @3 estimate', () => {
+    const result = parseInlineSyntax('Fix production memory leak !critical @3');
+    expect(result.title).toBe('Fix production memory leak');
+    expect(result.priority).toBe('critical');
+    expect(result.estimate).toBe(3);
+  });
+
+  it('retains default priority and estimate when no inline tags present', () => {
+    const result = parseInlineSyntax('Refactor API handlers', 'medium', 2);
+    expect(result.title).toBe('Refactor API handlers');
+    expect(result.priority).toBe('medium');
+    expect(result.estimate).toBe(2);
+  });
+
+  it('does not treat package versions as estimate shortcuts', () => {
+    const result = parseInlineSyntax('Upgrade React@18');
+    expect(result.title).toBe('Upgrade React@18');
+    expect(result.estimate).toBeNull();
+  });
+});