Add task management page with dual view modes (list table and kanban
columns). Tasks are fetched from the gateway API and displayed with
status badges, priority indicators, and due dates. Kanban columns
map to task statuses: not-started, in-progress, blocked, done.
Components: TaskCard, KanbanBoard, TaskListView
Types: Task, TaskStatus, TaskPriority, Project, ProjectStatus
Refs #29
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>