feat(frontend): implement main dashboard page (#48)

Implement the main dashboard / projects list page for Syndarix as the landing
page after login. The implementation includes:

Dashboard Components:
- QuickStats: Overview cards showing active projects, agents, issues, approvals
- ProjectsSection: Grid/list view with filtering and sorting controls
- ProjectCardGrid: Rich project cards for grid view
- ProjectRowList: Compact rows for list view
- ActivityFeed: Real-time activity sidebar with connection status
- PerformanceCard: Performance metrics display
- EmptyState: Call-to-action for new users
- ProjectStatusBadge: Status indicator with icons
- ComplexityIndicator: Visual complexity dots
- ProgressBar: Accessible progress bar component

Features:
- Projects grid/list view with view mode toggle
- Filter by status (all, active, paused, completed, archived)
- Sort by recent, name, progress, or issues
- Quick stats overview with counts
- Real-time activity feed sidebar with live/reconnecting status
- Performance metrics card
- Create project button linking to wizard
- Responsive layout for mobile/desktop
- Loading skeleton states
- Empty state for new users

API Integration:
- useProjects hook for fetching projects (mock data until backend ready)
- useDashboardStats hook for statistics
- TanStack Query for caching and data fetching

Testing:
- 37 unit tests covering all dashboard components
- E2E test suite for dashboard functionality
- Accessibility tests (keyboard nav, aria attributes, heading hierarchy)

Technical:
- TypeScript strict mode compliance
- ESLint passing
- WCAG AA accessibility compliance
- Mobile-first responsive design
- Dark mode support via semantic tokens
- Follows design system guidelines

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/tests/components/projects/ProjectHeader.test.tsx

@@ -0,0 +1,145 @@
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { ProjectHeader } from '@/components/projects/ProjectHeader';
+import type { Project } from '@/components/projects/types';
+
+const mockProject: Project = {
+  id: 'proj-001',
+  name: 'Test Project',
+  description: 'A test project for unit testing',
+  status: 'in_progress',
+  autonomy_level: 'milestone',
+  created_at: '2025-01-15T00:00:00Z',
+  owner_id: 'user-001',
+};
+
+describe('ProjectHeader', () => {
+  it('renders project name', () => {
+    render(<ProjectHeader project={mockProject} />);
+    expect(screen.getByText('Test Project')).toBeInTheDocument();
+  });
+
+  it('renders project description', () => {
+    render(<ProjectHeader project={mockProject} />);
+    expect(screen.getByText('A test project for unit testing')).toBeInTheDocument();
+  });
+
+  it('renders project status badge', () => {
+    render(<ProjectHeader project={mockProject} />);
+    expect(screen.getByText('In Progress')).toBeInTheDocument();
+  });
+
+  it('renders autonomy level badge', () => {
+    render(<ProjectHeader project={mockProject} />);
+    expect(screen.getByText('Milestone')).toBeInTheDocument();
+  });
+
+  it('renders nothing when project is null', () => {
+    const { container } = render(<ProjectHeader project={null} />);
+    expect(container.firstChild).toBeNull();
+  });
+
+  it('shows loading skeleton when isLoading is true', () => {
+    const { container } = render(<ProjectHeader project={null} isLoading />);
+    expect(container.querySelectorAll('.animate-pulse').length).toBeGreaterThan(0);
+  });
+
+  it('shows pause button when canPause is true and project is in_progress', () => {
+    const onPauseProject = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        canPause={true}
+        onPauseProject={onPauseProject}
+      />
+    );
+    expect(screen.getByRole('button', { name: /pause project/i })).toBeInTheDocument();
+  });
+
+  it('does not show pause button when project is not in_progress', () => {
+    const completedProject = { ...mockProject, status: 'completed' as const };
+    render(<ProjectHeader project={completedProject} canPause={true} />);
+    expect(screen.queryByRole('button', { name: /pause project/i })).not.toBeInTheDocument();
+  });
+
+  it('shows run sprint button when canStart is true', () => {
+    const onStartSprint = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        canStart={true}
+        onStartSprint={onStartSprint}
+      />
+    );
+    expect(screen.getByRole('button', { name: /run sprint/i })).toBeInTheDocument();
+  });
+
+  it('does not show run sprint button when project is completed', () => {
+    const completedProject = { ...mockProject, status: 'completed' as const };
+    render(<ProjectHeader project={completedProject} canStart={true} />);
+    expect(screen.queryByRole('button', { name: /run sprint/i })).not.toBeInTheDocument();
+  });
+
+  it('calls onStartSprint when run sprint button is clicked', async () => {
+    const user = userEvent.setup();
+    const onStartSprint = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        canStart={true}
+        onStartSprint={onStartSprint}
+      />
+    );
+
+    await user.click(screen.getByRole('button', { name: /run sprint/i }));
+    expect(onStartSprint).toHaveBeenCalledTimes(1);
+  });
+
+  it('calls onPauseProject when pause button is clicked', async () => {
+    const user = userEvent.setup();
+    const onPauseProject = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        canPause={true}
+        onPauseProject={onPauseProject}
+      />
+    );
+
+    await user.click(screen.getByRole('button', { name: /pause project/i }));
+    expect(onPauseProject).toHaveBeenCalledTimes(1);
+  });
+
+  it('calls onCreateSprint when new sprint button is clicked', async () => {
+    const user = userEvent.setup();
+    const onCreateSprint = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        onCreateSprint={onCreateSprint}
+      />
+    );
+
+    await user.click(screen.getByRole('button', { name: /new sprint/i }));
+    expect(onCreateSprint).toHaveBeenCalledTimes(1);
+  });
+
+  it('calls onSettings when settings button is clicked', async () => {
+    const user = userEvent.setup();
+    const onSettings = jest.fn();
+    render(
+      <ProjectHeader
+        project={mockProject}
+        onSettings={onSettings}
+      />
+    );
+
+    await user.click(screen.getByRole('button', { name: /project settings/i }));
+    expect(onSettings).toHaveBeenCalledTimes(1);
+  });
+
+  it('applies custom className', () => {
+    render(<ProjectHeader project={mockProject} className="custom-class" />);
+    expect(screen.getByTestId('project-header')).toHaveClass('custom-class');
+  });
+});