fix: CI venv hash-cache + sector exposure renderer + auditor registration

- ci.yml: venv 해시 기반 캐싱 적용 (validate_specs.py md5 기준), requirements.txt 불필요 스텝 제거
- harness_coverage_auditor.py: sector_trend_analysis.py, etf_representative_monitor.py PY_FILES 등록
- render_operational_report.py: _portfolio_sector_exposure_summary 개선 — account_snapshot 실데이터 집계 + Top5 섹터별 상위 보유 종목 상세 테이블 + _display() 누락값 표시
- update_workbook_sector_insights.py: row-2 헤더 처리 + sector_holdings 상세 추적 + _display() 누락값 표시
- operational_report_contract.py: portfolio_sector_exposure_summary REPORT_SECTION_ORDER 등록
- validate_report_section_completeness_v1.py: 동일 섹션 추가
- build_architecture_boundaries_v2.py: sparkline/idx/basket-delta UI 프리미티브 whitelist 추가
- runtime/refactor_baseline_v1.yaml: 엔트로피 베이스라인 갱신 (1692 files, gate=PASS)

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

runtime/refactor_baseline_v1.yaml

@@ -1,9 +1,9 @@
 {
   "formula_id": "AUDIT_REPOSITORY_ENTROPY_V2",
   "gate": "PASS",
-  "total_file_count": 1685,
-  "package_script_count": 16,
-  "temp_json_count": 152,
+  "total_file_count": 1692,
+  "package_script_count": 17,
+  "temp_json_count": 154,
   "budget": {
     "schema_version": "repository_entropy_budget.v1",
     "max_total_files": 2200,
@@ -15,5 +15,5 @@
       "keep package scripts within release envelope"
     ]
   },
-  "source_zip_sha256": "8ce41081b6fcd8844a3e914b29bbd5a9469aed052a46f5549c799af72567762c"
+  "source_zip_sha256": "dcc27d38243ebb495b2eee109aaa5c820d7d097010e5549a1e47960a1e8d668f"
 }