fix: routing_gate 실측 PASS 확인 + spec/30 보정 + DAG step_count 68 갱신

- spec/30: routing_gate FAIL→PASS (2026-06-14 실측: SHORT=12.5% MID=50.0% LONG=37.5%)
  pass/fail 카운트 9/8→10/7 (58.82%), reason 7개 기준 미달로 갱신
- spec/13: FACTOR_LIFECYCLE_COMPLETENESS_V1 formula 등록
- spec/41: step_count 67→68 (validate_factor_lifecycle_completeness 기존 포함 확인)
- tools/build_horizon_rebalance_plan_v1.py: docstring 갱신 (MID/LONG 상한 명시)

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

spec/41_release_dag.yaml

@@ -1,5 +1,5 @@
 schema_version: release_dag.v3
-step_count: 67
+step_count: 68
 goal: Linearize package.json scripts into a validated DAG execution graph.
 execution_order:
   # 토폴로지 정렬 기준 병렬 실행 wave (의존성 없는 노드들을 동시에 실행 가능)