feat: integrate platform backend and application interfaces

server/migrations/0003_v1_indexes.sql

@@ -0,0 +1,3 @@
+CREATE INDEX IF NOT EXISTS generation_tasks_user_created_idx ON generation_tasks(user_id, created_at DESC);
+CREATE INDEX IF NOT EXISTS generation_attempts_task_sequence_idx ON generation_attempts(task_id, sequence);
+CREATE INDEX IF NOT EXISTS audit_logs_created_idx ON audit_logs(created_at DESC);