Fix task deletion FK constraint error

Delete child records (task_run_logs) before parent (scheduled_tasks) to avoid foreign key constraint violation when cancelling tasks.

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

src/db.ts

@@ -175,8 +175,9 @@ export function updateTask(id: string, updates: Partial<Pick<ScheduledTask, 'pro
 }
 
 export function deleteTask(id: string): void {
-  db.prepare('DELETE FROM scheduled_tasks WHERE id = ?').run(id);
+  // Delete child records first (FK constraint)
   db.prepare('DELETE FROM task_run_logs WHERE task_id = ?').run(id);
+  db.prepare('DELETE FROM scheduled_tasks WHERE id = ?').run(id);
 }
 
 export function getDueTasks(): ScheduledTask[] {