Add one-off tasks/appointments feature

- DB: tasks table with scheduled_datetime, reminder_minutes_before, advance_notified, status
- API: CRUD routes GET/POST /api/tasks, PATCH/DELETE /api/tasks/<id>
- Scheduler: check_task_reminders() fires advance + at-time notifications, tracks advance_notified to prevent double-fire
- Bot: handle_task() with add/list/done/cancel/delete actions + datetime resolution helper
- AI: task interaction type + examples added to command_parser
- Web: task list page with overdue/notified color coding + new task form with datetime-local picker
- Nav: replaced Templates with Tasks in bottom nav

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

synculous-client/src/lib/api.ts

@@ -1,5 +1,18 @@
 const API_URL = '';
 
+export interface Task {
+  id: string;
+  user_uuid: string;
+  title: string;
+  description?: string;
+  scheduled_datetime: string;
+  reminder_minutes_before: number;
+  advance_notified: boolean;
+  status: 'pending' | 'notified' | 'completed' | 'cancelled';
+  created_at: string;
+  updated_at: string;
+}
+
 function getToken(): string | null {
   if (typeof window === 'undefined') return null;
   return localStorage.getItem('token');
@@ -1052,6 +1065,17 @@ export const api = {
     },
   },
 
+  tasks: {
+    list: (status = 'pending') =>
+      request<Task[]>(`/api/tasks?status=${status}`, { method: 'GET' }),
+    create: (data: { title: string; description?: string; scheduled_datetime: string; reminder_minutes_before?: number }) =>
+      request<Task>('/api/tasks', { method: 'POST', body: JSON.stringify(data) }),
+    update: (id: string, data: Partial<Pick<Task, 'title' | 'description' | 'scheduled_datetime' | 'reminder_minutes_before' | 'status'>>) =>
+      request<Task>(`/api/tasks/${id}`, { method: 'PATCH', body: JSON.stringify(data) }),
+    delete: (id: string) =>
+      request<{ success: boolean }>(`/api/tasks/${id}`, { method: 'DELETE' }),
+  },
+
   ai: {
     generateSteps: (goal: string) =>
       request<{ steps: { name: string; duration_minutes: number }[] }>(